Breath-based control of a therapeutic treatment

• US 6,467,477 B1
• Filed: 03/15/2000
• Issued: 10/22/2002
• Est. Priority Date: 03/26/1999
• Status: Expired due to Term

• Current Assignee: RIC INVESTMENTS LLC (Respironics Incorporated)
• Original Assignee: Respironics Incorporated
• Inventors: Frank, John, Hill, Peter D.
• Primary Examiner(s): Lewis, Aaron J.
• Assistant Examiner(s): MITCHELL, TEENA KAY
• Application Number:
  US09/525,786
• Time in Patent Office: 951 Days
• Field of Search: 128/200.24, 128/204.18, 128/204.21, 128/204.23, 128/204.26, 128/204.12, 128/207.14
• US Class Current: 128/203.23
• CPC Class Codes: A61M 16/0063 Compressors
• 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 2205/3561 local, e.g. within room or hospital
• CPC Class Codes: A61M 2230/60 Muscle strain, i.e. measured on the user

Abstract

A system and method for providing a therapeutic treatment, such as a flow of breathing gas, to a patient at variable treatment levels. A respiratory cycle monitor detects the patient'"'"'s respiratory cycles and a control unit incrementally adjusts the treatment level from a first predetermined level to a second predetermined level over a first predetermined number of respiratory cycles. The amount of the incremental adjustment and the frequency of such adjustments over the course of the first predetermined number of respiratory cycles can be controlled to achieve a desired change in the therapeutic treatment over the course of the patient'"'"'s respiration.

Claims

1. A patient treatment system comprising:

treatment means for providing a therapeutic treatment to a patient at variable treatment levels;

respiratory cycle monitoring means for detecting a respiratory cycle of a patient; and

treatment modifying means for changing said treatment level from a first predetermined treatment level to a second predetermined treatment level over a first predetermined number of respiratory cycles of such a patient by adjusting an output of said treatment means a first predetermined amount over a second predetermined number of respiratory cycles of such a patient.

2. A patient treatment system according to claim 1, wherein:

(a) said treatment means is a system for delivering a flow of breathing gas to a patient,

(b) said respiratory cycle monitoring means is a sensor adapted to monitor a physiological characteristic of such a patient indicative of a respiratory cycle, and

(c) said treatment modifying means causes said system for delivering breathing gas to transition from one of a first predetermined pressure and a first predetermined flow to one of a second predetermined pressure and a second predetermined flow over said first predetermined number of respiratory cycles of such a patient by adjusting an output of said system for delivering breathing gas by said first predetermined amount over said second predetermined number of respiratory cycles of such a patient.

3. A patient treatment system according to claim 2, wherein said first predetermined pressure is a minimum pressure, said first predetermined flow is a minimum flow, said second predetermined pressure is a maximum pressure, said second predetermined flow is a maximum flow.

4. A patient treatment system according to claim 2, wherein said first predetermined pressure is a maximum pressure, said first predetermined flow is a maximum flow, said second predetermined pressure is a minimum pressure, said second predetermined flow is a minimum flow.

5. A patient treatment system according to claim 2, wherein:

(a) said system for delivering a flow of breathing gas to a patient comprises;

a pressure/flow generating means for supplying breathing gas at one of a selectable pressure and a selectable flow, and

a patient interface assembly operatively coupled to said pressure/flow generating means to communicate said supply of breathing gas from said pressure/flow generating means to an airway of a patient,

(b) said respiratory cycle monitoring means is a flow/pressure sensing system adapted to detect one of a flow of gas and a pressure of gas in said patient interface assembly and to output a signal indicative thereof, and

(c) said treatment modifying means includes a controller operatively coupled to said system for delivering breathing gas and to said flow sensing system for incrementally changing one of a pressure and a flow output by said system for delivering a flow of breathing gas based on said signal from said flow/pressure sensing system over at least one respiratory cycle of such a patient.

6. A patient treatment system according to claim 5, wherein said pressure/flow generating means includes:

a constant pressure/flow generator that outputs one of a constant predetermined pressure and a constant predetermined flow during normal operation, and

a breathing gas pressure/flow controller operatively coupled to said constant pressure/flow generator and said controller, wherein said breathing gas pressure/flow controller varies one of said constant predetermined pressure and said constant predetermined flow output from said constant pressure/flow generator based on an output from said controller to provide one of said selectable pressure and said selectable flow.

7. A patient treatment system according to claim 6, wherein said constant pressure/flow generator is selected from the group consisting of:

a pressurized tank of breathing gas, a blower, a piston, a bellows, a compressor, and a concentrator.

8. A patient treatment system according to claim 5, wherein said pressure/flow generating means is a variable pressure/flow generator that outputs one of (1) a variable pressure as said selectable pressure and (2) a variable flow as said selectable flow during normal operation based on an output of said controller.

9. A patient treatment system according to claim 8, wherein said variable pressure/flow generator comprises a blower and a variable speed motor operatively coupled to said blower and to said controller, wherein a speed of said variable speed motor is controlled based on said output from said controller.

10. A patient treatment system according to claim 5, wherein said patient interface assembly includes:

a conduit having a first end coupled to said pressure/flow generating means and a second end; and

a patient interface device coupled to said second end of said conduit for communicating a supply of breathing gas carried by said conduit to an airway of a patient.

11. A patient treatment system according to claim 5, wherein said controller determines an inspiratory phase and an expiratory phase of said respiratory cycle based on an output of said respiratory cycle monitoring means and independently adjusts said system for delivering a flow of breathing gas during said inspiratory phase and said expiratory phase so that, in at least one of said inspiratory phase and said expiratory phase, said system for delivering a flow of breathing gas transitions from one of said first predetermined pressure and said first predetermined flow to one of said second predetermined pressure and said second predetermined flow over said first predetermined number of respiratory cycles of such a patient by said first predetermined amount over said second predetermined number of respiratory cycles of such a patient.

12. A patient treatment system according to claim 1, wherein said respiratory cycle monitoring means is selected from the group consisting of:

(1) an acoustic system adapted to detect sounds associated with a patient'"'"'s respiration, (2) a motion detecting system adapted to detect movement of a patient associated with a patient'"'"'s respiration, (3) a temperature detecting system adapted to detect temperature variations associated with a patient'"'"'s respiration, (4) an electrical signal sensing system adapted to detect electrical activity of a patient associated with a patient'"'"'s respiration, (5) a pressure sensing system associated with a patient'"'"'s respiratory system to detect pressure variations induced by patient respiration, (6) a flow sensing system associated with a patient'"'"'s respiratory system to detect flow variations induced by patient respiration, and (7) a treatment means monitor that detects changes in operation of said treatment means resulting from patient respiration.

13. A patient treatment system according to claim 1, wherein

(a) said treatment system is a system for providing medication to a patient at variable dosage rates,

(b) said respiratory cycle monitoring means is a sensor adapted to monitor a physiological characteristic of such a patient indicative of a respiratory cycle, and

(c) said treatment modifying means causes said system for providing medication to transition from a first predetermined dosage rate to a second predetermined dosage rate over said first predetermined number of respiratory cycles of such a patient by adjusting an output of said system for providing medication by said first predetermined amount over said second predetermined number of respiratory cycles of such a patient.

14. A patient treatment system according to claim 1, wherein:

(a) said treatment means comprises;

a gas flow generator adapted to generate a flow of breathing gas,

a patient interface operatively associated with said gas flow generator to communicate said flow of breathing gas to an airway of a patient,

a pressure/flow controller associated with at least one of said gas flow generator and said patient interface to control one of a pressure and a flow of breathing gas provided to an airway of such a patient,

first means for establishing a first gain, and

control means, operatively coupled to said pressure/flow controller and said first means for establishing said first gain, for controlling one of said pressure and said flow of breathing gas based on a fluid characteristic signal and said first gain;

(b) wherein said respiratory cycle monitoring means comprises a sensor adapted to detect at least one fluid characteristic associated with a flow of gas within said patient interface and to provide said fluid characteristic signal that corresponds to said characteristic; and

(c) wherein said treatment modifying means causes said control means to adjust said first gain from a first predetermined level to a second predetermined level over said first predetermined number of respiratory cycles of such a patient by said first predetermined amount over said second predetermined number of respiratory cycles of such a patient.

15. A patient treatment system according to claim 14, wherein said at least one fluid characteristic is a rate of said flow of breathing gas within said patient interface.

16. A patient treatment system according to claim 14, wherein said treatment means further comprises a second means for establishing a second gain, said control means applying said first gain to a first fluid characteristic signal output said sensor, said first fluid characteristic signal corresponding to a fluid characteristic indicative of inspiration, and applying said second gain to a second fluid characteristic signal output by said sensor, said second fluid characteristic signal corresponding to a fluid characteristic indicative of expiration, and wherein said treatment modifying means also causes said control means to adjust said second gain from a third predetermined level to a fourth predetermined level over a third predetermined number of respiratory cycles of such a patient by a second predetermined amount over a fourth predetermined number of respiratory cycles of such a patient.

17. A patient treatment system according to claim 14, wherein said control means also controls one of said pressure and said flow of breathing gas based on one of a base pressure and a base flow rate in addition to said controlling said flow of breathing gas based on said first gain and said fluid characteristic signal, and wherein said treatment modifying means causes said control means to adjust one of said base pressure and said base flow rate from a first predetermined level to a second predetermined level over a third predetermined number of respiratory cycles of such a patient by said predetermined amount over a fourth predetermined number of respiratory cycles of such a patient.

18. A patient treatment system according to claim 1, wherein

(a) said treatment means comprises:

a gas flow generator adapted to generate a flow of breathing gas,

a patient interface operatively associated with said gas flow generator to communicate said flow of breathing gas to an airway of a patient,

a pressure/flow controller associated with at least one of said gas flow generator and said patient interface to control one of a pressure and a flow of breathing gas provided to an airway of such a patient,

first means for establishing a first gain and a second gain, and

control means, operatively coupled to said pressure/flow controller and said first means for establishing said first gain and said second gain, for controlling one of said pressure and said flow of breathing gas;

(b) wherein said respiratory cycle monitoring means comprises;

(1) means for determining a rate of said flow of breathing gas provided to such a patient and to provide a first signal corresponding to said rate of said flow of breathing gas, and

(2) means for determining a volume of breathing gas provided to such a patient and to provide a second signal corresponding to said volume, wherein said control means controls one of said pressure and said flow of breathing gas provided to a patient based on a first product of said first gain and said first signal in combination with a second product of said second gain and said second signal; and

(c) wherein said treatment modifying means causes said control means to adjust at least one of said first gain and said second gain from a first predetermined level to a second predetermined level over said first predetermined number of respiratory cycles of such a patient by said predetermined amount over said second predetermined number of respiratory cycles of such a patient.

19. A patient treatment system according to claim 1, wherein:

(a) said treatment means comprises;

a gas flow generator adapted to generate a flow of breathing gas,

a patient interface operatively associated with said gas flow generator to communicate said flow of breathing gas to an airway of a patient,

a pressure/flow controller associated with at least one of said gas flow generator and said patient interface to control one of a pressure and a flow of breathing gas provided to an airway of such a patient, and

control means, operatively coupled to said pressure/flow controller for controlling one of said pressure and said flow of breathing gas provided to a patient based on a product of said fluid characteristic signal and a gain in combination with one of a base pressure and a base flow rate;

(b) wherein said respiratory cycle monitoring means comprises a sensor adapted to detect at least one fluid characteristic associated with a flow of gas within said patient interface and to transmit said signal corresponding to said characteristic; and

(c) wherein said treatment modifying means causes said control means to adjust one of said base pressure and said base flow rate from one of a first predetermined pressure level and a first predetermined flow rate to one of a second predetermined pressure level said a second predetermined flow rate over said first predetermined number of respiratory cycles of such a patient by said predetermined amount over said second predetermined number of respiratory cycles of such a patient.

20. A patient treatment system according to claim 1, further comprising means for adjusting at least one of said first predetermined level, said second predetermined level, said first predetermined number of respiratory cycles, said second predetermined number of respiratory cycles, and said predetermined amount to control how said treatment changes over a plurality of respiratory cycles of such a patient.

21. A method of treating a patient comprising:

providing a therapeutic treatment to a patient at variable treatment levels;

detecting a respiratory cycle of such a patient; and

changing said treatment level from a first predetermined treatment level to a second predetermined treatment level over a first predetermined number of respiratory cycles of such a patient by adjusting a treatment level by a first predetermined amount over a second predetermined number of respiratory cycles of such a patient.

22. A method of treating a patient according to claim 21, wherein

(a) said step of providing a therapeutic treatment includes delivering a flow breathing gas to a patient,

(b) said detecting step includes monitoring a physiological characteristic of such a patient indicative of a respiratory cycle via a sensor, and

(c) said step of changing said treatment level includes transitioning one of a pressure and a flow of said breathing gas from one of a first predetermined pressure and a first predetermined flow to one of a second predetermined pressure and a second predetermined flow over said first predetermined number of respiratory cycles of such a patient by adjusting one of a flow and a pressure of said breathing gas by said first predetermined amount over said second predetermined number of respiratory cycles of such a patient.

23. A method of treating a patient according to claim 22, wherein:

(a) said step of delivering a breathing gas to a patient comprises;

supplying breathing gas to a patient at one of a selectable pressure and a selectable flow, and

communicating said supply of breathing gas to an airway of such a patient,

(b) said monitoring step includes detecting one of a flow of breathing gas and a pressure of breathing gas and outputting a signal indicative thereof, and

(c) said transitioning step includes incrementally changing one of a pressure and a flow of breathing gas provided in said breathing gas delivery step based on said signal.

24. A method of treating a patient according to claim 23, wherein said step of supplying breathing gas to a patient includes:

generating one of a constant predetermined pressure and a constant predetermined flow;

regulating one of said constant predetermined pressure and said constant predetermined flow to produce one of said selectable pressure and said selectable flow.

25. A method of treating a patient according to claim 23, wherein said step of supplying breathing gas to a patient includes:

generating one of a variable pressure and a variable flow as an associated one of said selectable pressure and said selectable flow via a variable speed pressure/flow generating device; and

controlling a speed of said variable speed pressure/flow generating device.

26. A method of treating a patient according to claim 23, wherein said monitoring step includes determining an inspiratory phase and an expiratory phase of said respiratory cycle based at least one of said detected flow and said detected pressure of breathing gas, and wherein said transitioning step includes independently adjusting one of said selectable pressure and said selectable flow of said breathing gas during said inspiratory phase and said expiratory phase so that in at least one of said inspiratory phase and said expiratory phase said supply of breathing gas transitions from one of said first predetermined pressure and said first predetermined flow to one of said second predetermined pressure and said second predetermined flow over said first predetermined number of respiratory cycles of such a patient by said first predetermined amount over said second predetermined number of respiratory cycles of such a patient.

27. A method of treating a patient according to claim 21, wherein

(a) providing a therapeutic treatment includes providing a medication to a patient at variable dosage rates,

(b) detecting a respiratory cycle includes detecting, via a sensor associated with a patient, a physiological characteristic of such a patient indicative of a respiratory cycle, and

(c) changing said treatment level includes causing said dosage rate of medication to transition from a first predetermined dosage rate to a second predetermined dosage rate over said first predetermined number of respiratory cycles of such a patient by adjusting an output of said system for providing medication by said first predetermined amount over said second predetermined number of respiratory cycles of such a patient.

28. A method of treating a patient according to claim 21, wherein

(a) providing a therapeutic treatment includes:

generating a flow of breathing gas,

communicating said flow of breathing gas to an airway of a patient,

establishing a first gain, and

controlling one of a pressure and a flow of breathing gas provided to a patient based on a fluid characteristic signal and said first gain;

(b) detecting a respiratory cycle includes detecting, via a sensor, at least one fluid characteristic associated with a flow of breathing gas to a patient and providing said fluid characteristic signal corresponding to said detected characteristic; and

(c) changing said treatment level includes adjusting said first gain from a first predetermined level to a second predetermined level over said first predetermined number of respiratory cycles of such a patient by said first predetermined amount over said second predetermined number of respiratory cycles of such a patient.

29. A method of treating a patient according to claim 28, wherein detecting at least one fluid characteristic includes detecting a rate of said flow of breathing gas.

30. A method of treating a patient according to claim 28, wherein

(a) controlling one of a pressure and a flow of breathing gas provided to a patient includes controlling one of said pressure and said flow of breathing gas based on one of a base pressure and a base flow rate in addition to controlling said flow of breathing gas based on said first gain and said fluid characteristic signal, and

(b) changing said treatment level includes adjusting one of said base pressure and said base flow rate from a first predetermined level to a second predetermined level over a third predetermined number of respiratory cycles of such a patient by said predetermined amount over a fourth predetermined number of respiratory cycles of such a patient.

31. A method of treating a patient according to claim 21, wherein

(a) providing a therapeutic treatment includes:

generating a flow of breathing gas,

communicating said flow of breathing gas to an airway of a patient,

establishing a first gain and a second gain, and

controlling one of a pressure and a flow of breathing gas provided to a patient;

(b) detecting a respiratory cycle includes;

determining a rate of said flow of breathing gas provided to such a patient and providing a first signal corresponding to said rate of said flow of breathing gas, and

determining a volume of breathing gas provided to such a patient and providing a second signal corresponding to said volume,

wherein controlling one of a pressure and a flow of breathing gas provided to a patient includes controlling one of said pressure and said flow of breathing gas based on a first product of said first gain and said first signal in combination with a second product of said second gain and said second signal; and

(c) changing said treatment level includes adjusting at least one of said first gain and said second gain from a first predetermined level to a second predetermined level over said first predetermined number of respiratory cycles of such a patient by said first predetermined amount over said second predetermined number of respiratory cycles of such a patient.

32. A method of treating a patient according to claim 21, wherein

(a) providing a therapeutic treatment includes:

generating a flow of breathing gas,

communicating said flow of breathing gas to an airway of a patient,

controlling one of a pressure and a flow of breathing gas provided to a patient based on a product of a fluid characteristic signal and a gain in combination with one of a base pressure and a base flow rate;

(b) detecting a respiratory cycle includes detecting, via a sensor, at least one fluid characteristic associated with a flow of breathing gas to a patient and providing said fluid characteristic signal corresponding to said detected characteristic; and

(c) changing said treatment level includes adjusting one of said base pressure and said base flow rate from one of a first predetermined pressure level and a first predetermined flow rate to one of a second predetermined pressure level said a second predetermined flow rate over said first predetermined number of respiratory cycles of such a patient by said predetermined amount over said second predetermined number of respiratory cycles of such a patient.

33. A method of treating a patient according to claim 21, further comprising adjusting at least one of said first predetermined level, said second predetermined level, said first predetermined number of respiratory cycles, said second predetermined number of respiratory cycles, and said predetermined amount to control how said treatment changes over a plurality of respiratory cycles of such a patient.