Claims
- 1. An auto-titration pressure support system comprising:
a pressure generating system adapted to generate a flow of breathing gas at a selectable pressure level; a patient circuit having a first end adapted to be coupled to the pressure generating system and a second end adapted to be coupled to an airway of a patient; a monitoring system associated with the patient circuit or the pressure generating system and adapted to measure a parameter indicative of a pressure at a patient's airway, a flow of gas in such a patient's airway, or both and to output a pressure signal, a flow signal indicative thereof, respectively, or both; and a controller coupled to the monitoring system and the pressure generating system, for controlling a pressure of the flow of breathing gas output by the pressure generating system based on the output of the monitoring system, wherein the controller is programmed to operate according to one control layer in a set of prioritized control layers, wherein each control layer in the set of prioritized control layers competes for control of the pressure generating system with the other control layers, and wherein each control layer implements a unique pressure control process for controlling the pressure of the flow of breathing gas output by the pressure generating system.
- 2. The system of claim 1, wherein each control layer in the set of prioritized control layer includes:
a detection module that receives the pressure signal, the flow signal or both; a monitoring module that monitors an output of the detection module to determine whether to request that the control layer take control of the pressure generating system; and a control module that control the operation of the pressure generating system responsive to the control layer being granted control thereof.
- 3. The system of claim 1, wherein the set of prioritized control layers include:
(a) flow limit control layer that monitors the flow signal to determine whether the pressure generating system is exhibiting a large leak indicative of the patient circuit not being connected to an airway of a patient, and causes the pressure generating system to lower the pressure of the flow of breathing gas responsive to detection of the large leak and maintains the pressure generating system at the lower pressure; (b) snore control layer that monitors the flow signal, the pressure signal, or both for snoring, and causes the pressure generating system to increase the pressure of the flow of breathing gas responsive to detection of snore; (c) a big leak control layer that monitors the flow signal to determine whether the pressure generating system is exhibiting a leak that is less than the large leak but great enough to cause the pressure support system to not operate reliably, and causes the pressure generating system to lower the pressure of the flow of breathing gas responsive to detection of the large leak for predetermined period of time; (d) an apnea/hypopnea control layer that monitors the flow signal, the pressure signal, or both to determine whether the patient is experiencing an apnea, a hypopnea, or both, and causes the pressure generating system to adjust the pressure of the flow of breathing gas responsive to detection of apnea, hypopnea or both; (e) a variable breathing control layer that monitors the flow signal to determine whether the patient is experiencing erratic breathing, and causes the pressure generating system to adjust the pressure of the flow of breathing gas responsive to detection of erratic breathing; and (f) an auto-CPAP control layer that controls the pressure of the flow of breathing gas responsive to proactively search for a pressure that optimizes the pressure provided to the patient to treat disordered breathing.
- 4. The system of claim 3, wherein:
(1) the flow limit control layer has a higher priority than the snore control layer, the big leak control layer, the apnea/hypopnea control layer, the variable breathing control layer, and the auto-CPAP control layer; (2) the snore control layer has a higher priority than the big leak control layer, the apnea/hypopnea control layer, the variable breathing control layer, and the auto-CPAP control layer and has a lower priority than the flow limit control layer; (3) the big leak control layer has a higher priority than the apnea/hypopnea control layer, the variable breathing control layer, and the auto-CPAP control layer and has a lower priority than the flow limit control layer and the snore control layer; (4) the apnea/hypopnea control layer has a higher priority than the variable breathing control layer, and the auto-CPAP control layer and has a lower priority than the flow limit control layer, the snore control layer and the big leak control layer; and (5) the variable breathing control layer has a higher priority than the auto-CPAP control layer and has a lower priority than the flow limit control layer, the snore control layer, the big leak control layer, and the apnea/hypopnea control layer.
- 5. The system of claim 1, further comprising a manual input for controlling the operation of the pressure support system, and wherein the set of prioritized control layers include at least one first control layer that is initiated based on the manual input and at least one second control layer that is initiated based on the pressure signal, the flow signal or both, wherein the at least one first control layer has a higher priority than the at least one second control layer.
- 6. The system of claim 5, wherein the first control layer is a ramp control layer that causes the pressure generating system to gradually increase the pressure of the flow of breathing gas from a relatively low level to a target level responsive to receipt of a ramp activation signal as the manual input.
- 7. The system of claim 6, wherein the second control layer includes at least one of the following control layers:
(a) flow limit control layer that monitors the flow signal to determine whether the pressure generating system is exhibiting a large leak indicative of the patient circuit not being connected to an airway of a patient, and causes the pressure generating system to lower the pressure of the flow of breathing gas responsive to detection of the large leak and maintains the pressure generating system at the lower pressure; (b) snore control layer that monitors the flow signal, the pressure signal, or both for snoring, and causes the pressure generating system to increase the pressure of the flow of breathing gas responsive to detection of snore; (c) a big leak control layer that monitors the flow signal to determine whether the pressure generating system is exhibiting a leak that is less than the large leak but great enough to cause the pressure support system to not operate reliably, and causes the pressure generating system to lower the pressure of the flow of breathing gas responsive to detection of the large leak for predetermined period of time; (d) an apnea/hypopnea control layer that monitors the flow signal, the pressure signal, or both to determine whether the patient is experiencing an apnea, a hypopnea, or both, and causes the pressure generating system to adjust the pressure of the flow of breathing gas responsive to detection of apnea, hypopnea or both; (e) a variable breathing control layer that monitors the flow signal to determine whether the patient is experiencing erratic breathing, and causes the pressure generating system to adjust the pressure of the flow of breathing gas responsive to detection of erratic breathing; and (f) an auto-CPAP control layer that controls the pressure of the flow of breathing gas responsive to actively search for a pressure that optimizes the pressure provided to the patient to treat disordered breathing.
- 8. A method of providing pressure support to a patient, comprising:
providing flow of breathing gas at a selectable pressure level to an airway of a patient; monitoring a pressure, a flow, or both of the flow of breathing gas and outputting a pressure signal, a flow signal indicative thereof, respectively, or both; selecting a control layer from a set of prioritized control layers based on the pressure signal, the flow signal, or both; and controlling a pressure of the flow of breathing gas according to a pressure control technique unique to the selected pressure control layer.
- 9. The method of claim 8, wherein the set of prioritized control layers include:
(a) flow limit control layer that monitors the flow signal to determine whether the pressure generating system is exhibiting a large leak indicative of the patient circuit not being connected to an airway of a patient, and causes the pressure generating system to lower the pressure of the flow of breathing gas responsive to detection of the large leak and maintains the pressure generating system at the lower pressure; (b) snore control layer that monitors the flow signal, the pressure signal, or both for snoring, and causes the pressure generating system to increase the pressure of the flow of breathing gas responsive to detection of snore; (c) a big leak control layer that monitors the flow signal to determine whether the pressure generating system is exhibiting a leak that is less than the large leak but great enough to cause the pressure support system to not operate reliably, and causes the pressure generating system to lower the pressure of the flow of breathing gas responsive to detection of the large leak for predetermined period of time; (d) an apnea/hypopnea control layer that monitors the flow signal, the pressure signal, or both to determine whether the patient is experiencing an apnea, a hypopnea, or both, and causes the pressure generating system to adjust the pressure of the flow of breathing gas responsive to detection of apnea, hypopnea or both; (e) a variable breathing control layer that monitors the flow signal to determine whether the patient is experiencing erratic breathing, and causes the pressure generating system to adjust the pressure of the flow of breathing gas responsive to detection of erratic breathing; and (f) an auto-CPAP control layer that controls the pressure of the flow of breathing gas responsive to actively search for a pressure that optimizes the pressure provided to the patient to treat disordered breathing.
- 10. The method of claim 9, wherein selecting a control layer includes:
(1) selecting the flow limit control layer over the snore control layer, the big leak control layer, the apnea/hypopnea control layer, the variable breathing control layer, and the auto-CPAP control layer; (2) selecting the snore control layer over the big leak control layer, the apnea/hypopnea control layer, the variable breathing control layer, and the auto-CPAP control layer but not over the flow limit control layer; (3) selecting the big leak control layer over the apnea/hypopnea control layer, the variable breathing control layer, and the auto-CPAP control layer but not over the flow limit control layer and the snore control layer; (4) selecting the apnea/hypopnea control layer over the variable breathing control layer and the auto-CPAP control layer but not over the flow limit control layer, the snore control layer and the big leak control layer; and (5) selecting the variable breathing control layer over the auto-CPAP control layer but not over the flow limit control layer, the snore control layer, the big leak control layer, and the apnea/hypopnea control layer.
- 11. The method of claim 8, further comprising receiving a manual input for controlling the operation of the pressure support system, wherein the set of prioritized control layers include at least one first control layer that is initiated based on the manual input and at least one second control layer that is initiated based on the pressure signal, the flow signal or both, wherein the selecting step includes selecting the at least one first control layer over the at least one second control layer.
- 12. An auto-titration pressure support system comprising:
a pressure generating system adapted to generate a flow of breathing gas at a selectable pressure level; a patient circuit having a first end adapted to be coupled to the pressure generating system and a second end adapted to be coupled to an airway of a patient; a monitoring system associated with the patient circuit or the pressure generating system and adapted to measure a parameter indicative of a flow of gas in such a patient's airway and to output a flow signal indicative thereof; and a controller coupled to the monitoring system and the pressure generating system, for controlling the pressure generating system based on the output of the monitoring system, wherein the controller performs a trend analysis on the output of the monitoring system.
- 13. The system of claim 12, wherein the controller determines a plurality of values for a monitored breath parameter over a period of time and performs a long-term trend analysis and a short-term trend analysis on the plurality of values for the monitored breath parameter in deciding whether to cause the pressure generating system to adjust the pressure level of the flow of breathing gas.
- 14. The system of claim 13, wherein a result of the long-term trend analysis and a short-term trend analysis for each monitored breath parameter are used to determine a trend analysis vote associated with each monitored breath parameter, wherein the trend analysis votes for a plurality of monitored breath parameters are accumulated to determine a final vote value, and wherein the controller causes the pressure generating system to adjust the pressure level of the flow of breathing gas based on the final vote value.
- 15. The system of claim 12, wherein the controller determines one value for a monitored breath parameter for each respiratory cycle and averages a plurality of the values for the monitored breathing parameter to determine a single point value, and wherein the controller uses a plurality of the single points values in performing the trend analysis.
- 16. The system of claim 15, wherein the controller determines a best-fit line for a plurality of the single point values and calculates a percent change of the best-fit line, a difference value for the best-fit line, or both.
- 17. The system of claim 15, wherein the controller performs a long-term trend analysis by determining a trend error window for the best-fit line and comparing the trend error window to at least one threshold.
- 18. The system of claim 15, wherein the controller performs a short-term trend analysis by (1) comparing a newly generated single point value to a prediction interval, wherein the prediction interval is determined by the controller based at least in part on a standard deviation of single point values used in determining a best-fit line for the plurality of single point values and (2) comparing a newly generated single point value to a start of trend data point, which is a single point value on the best-fit line at a start of data used in determining the best-fit line.
- 19. A method or providing pressure support system to a patient, comprising:
providing flow of breathing gas at a selectable pressure level to an airway of a patient; monitoring a flow of the flow of breathing gas and outputting a flow signal indicative thereof; performing a trend analysis on data determined from the flow signal; and controlling a pressure of the flow of breathing gas based on the trend analysis.
- 20. The method of claim 19, wherein performing a trend analysis includes:
determining a plurality of values for a monitored breath parameter over a period of time; performing a long-term trend analysis on the plurality of values for the monitored breath parameter; and performing a short-term trend analysis on the plurality of values for the monitored breath parameter.
- 21. The method of claim 20, wherein performing the trend analysis further includes:
determining a trend analysis vote associated with each monitored breath parameter based on a result of the long-term trend analysis and a short-term trend analysis; accumulating the trend analysis votes for a plurality of monitored breath parameters to determine a final vote value, and wherein the pressure is controlled in the pressure controlling step based on the final vote value.
- 22. The method of claim 19, wherein performing the trend analysis includes:
determining one value for a monitored breath parameter for each respiratory cycle; and averaging a plurality of the values for the monitored breathing parameter to determine a single point value.
- 23. The method of claim 22, wherein performing the trend analysis further includes:
determining a best-fit line for a plurality of the single point values; and calculating a percent change of the best-fit line, a difference value for the best-fit line, or both.
- 24. The method of claim 23, wherein performing the trend analysis includes:
performing a long-term trend analysis by determining a trend error window for the best-fit line; and comparing the trend error window to at least one threshold.
- 25. The system of claim 23, wherein performing the trend analysis includes performing a short-term trend analysis by (1) comparing a newly generated single point value to a prediction interval, wherein the prediction interval is determined by the controller based at least in part on a standard deviation of single point values used in determining a best-fit line for the plurality of single point values and (2) comparing a newly generated single point value to a start of trend data point, which is a single point value on the best-fit line at a start of data used in determining the best-fit line.
- 26. An auto-titration pressure support system comprising:
a pressure generating system adapted to generate a flow of breathing gas at a selectable pressure level; a patient circuit having a first end adapted to be coupled to the pressure generating system and a second end adapted to be coupled to an airway of a patient; a monitoring system associated with the patient circuit or the pressure generating system and adapted to measure a parameter indicative of a flow of gas in such a patient's airway and to output a flow signal indicative thereof; and a controller coupled to the monitoring system and the pressure generating system, for controlling the pressure generating system based on the output of the monitoring system, wherein the controller determines a breathing parameter from the flow signal, and wherein the controller analyzes a variability of the breathing parameter and controls the pressure generating system based on a result of the variability analysis.
- 27. The system of claim 26, wherein analyzing the variability of the breathing parameter includes calculating a weighted peak flow and a best-fit trend line for the weighted peak flow over a plurality of breathing cycles, and calculating a variable breathing number (VB#) as follows:
- 28. The system of claim 27, wherein a relationship between the adjusted mean flow and the actual patient flow varies based on the flow signal.
- 29. The system of claim 27, wherein the controller compares the variable breathing number to a first threshold and causes the pressure generating system to control the pressure of the flow of breathing gas as follows responsive to the variable breathing number exceeding the first threshold:
(1) maintain the pressure at a constant level if the pressure of the flow of breathing gas was not increasing or decreasing when variability of the breathing parameter is detected; (2) decrease the pressure if the pressure of the flow of breathing gas was increasing when variability of the breathing parameter is detected; and (3) increase the pressure if the pressure of the flow of breathing gas was decreasing when variability of the breathing parameter is detected.
- 30. A method of providing pressure support to a patient, comprising:
providing flow of breathing gas at a selectable pressure level to an airway of a patient; monitoring a flow of the flow of breathing gas and outputting a flow signal indicative thereof,
determining a breathing parameter from the flow signal; analyzing a variability of the breathing parameter; and controlling a pressure of the flow of breathing gas based on a result of the variability analysis.
- 31. The method of claim 30, wherein analyzing the variability of the breathing parameter includes:
calculating a weighted peak flow and a best-fit trend line for the weighted peak flow over a plurality of breathing cycles; and calculating a variable breathing number (VB#) as follows: 10VB#=standard deviationadjusted mean flow,wherein the standard deviation is calculated as a standard deviation of the weighted peak flows over a plurality of breathing cycles from the best-fit trend line, and wherein the adjusted mean flow is determined based on an actual patient flow determined from the flow signal.
- 32. The method of claim 31, further comprising selecting the adjusted mean flow based on a value of the flow signal, where there is a non-linear relationship between the value of the flow signal and the adjusted mean flow.
- 33. The method of claim 31, wherein analyzing a variability of the breathing parameter includes comparing the variable breathing number to a first threshold, and wherein controlling the pressure of the flow of breathing gas is performed as follows responsive to the variable breathing number exceeding the first threshold:
(1) maintain the pressure at a constant level if the pressure of the flow of breathing gas was not increasing or decreasing when variability of the breathing parameter is detected; (2) decrease the pressure if the pressure of the flow of breathing gas was increasing when variability of the breathing parameter is detected; and (3) increase the pressure if the pressure of the flow of breathing gas was decreasing when variability of the breathing parameter is detected.
- 34. An auto-titration pressure support system comprising:
a pressure generating system adapted to generate a flow of breathing gas at a selectable pressure level; a patient circuit having a first end adapted to be coupled to the pressure generating system and a second end adapted to be coupled to an airway of a patient; a monitoring system associated with the patient circuit or the pressure generating system and adapted to measure a parameter indicative of a pressure at a patient's airway and a flow of gas in such a patient's airway and to output a pressure signal and a flow signal indicative thereof; and a controller coupled to the monitoring system and the pressure generating system, for controlling the pressure generating system based on the output of the monitoring system, wherein the controller monitors leakage of gas from the patient circuit based on the flow signal, the pressure signal, or both and reduces a pressure provided to a patient by the pressure generating system for a predetermined period of time responsive to a determination that a rate of the leakage of gas exceeds a predetermined threshold, and wherein the controller continues to deliver a therapeutic pressure support treatment to the patient by causing the pressure generating system to continue to deliver the flow of breathing gas a reduced level that is a level sufficient to provide a therapeutic treatment to such a patient.
- 35. A method of providing pressure support to a patient, comprising:
providing flow of breathing gas at a selectable pressure level to an airway of a patient via a patient circuit in fluid communication with an airway of a patient defining a closed system; monitoring a pressure and a flow of the flow of breathing gas and outputting a pressure signal and a flow signal indicative thereof, respectively; determining a rate of leakage of gas from the closed system based on the pressure signal, the flow signal, or both; reducing the pressure of the flow of breathing for a predetermined period of time responsive to a determination that the rate of the leakage of gas exceeds a predetermined threshold; and continuing to deliver the flow of breathing gas at a reduced level, wherein the reduced level is a level sufficient to provide a therapeutic treatment to such a patient.
- 36. An auto-titration pressure support system comprising:
a pressure generating system adapted to generate a flow of breathing gas at a selectable pressure level; a patient circuit having a first end adapted to be coupled to the pressure generating system and a second end adapted to be coupled to an airway of a patient; a monitoring system associated with the patient circuit or the pressure generating system and adapted to measure a parameter indicative of a flow of gas in such a patient's airway and to output a flow signal indicative thereof; and a controller coupled to the monitoring system and the pressure generating system, for controlling the pressure generating system based on the output of the monitoring system, wherein the controller determines a skewness of a patient's inspiratory waveforms from the output of the flow sensor and controls the pressure generating system according to the skewness determination.
- 37. The system of claim 36, wherein the controller determines the skewness of the inspiratory waveform by segmenting the inspiratory waveform into a first region that corresponds to a beginning portion of the inspiratory waveform and a second region that corresponds to a middle portion of the inspiratory waveform, and comparing the flow in the second region to the flow in the first region.
- 38. The system of claim 37, wherein the flow in the first region corresponds to an average of the highest rates of flow in the first region, and wherein the flow in the second region corresponds to an average of the highest rates of flow in the second region.
- 39. The system of claim 37, wherein the first region corresponds to approximately a first third of the inspiratory waveform and the second region corresponds to approximately a second third of the inspiratory waveform, and wherein the highest flow rates in the first region and the second region are defined as the flow rates within 5% of the highest flow rates in each region.
- 40. The system of claim 37, wherein the skewness is calculated as a skewness number follows:
- 41. The system of claim 40, wherein the controller causes the pressure generating system to increase the pressure of the flow of breathing gas responsive to a decrease in the skewness number.
- 42. A method or providing pressure support system to a patient, comprising:
providing flow of breathing gas at a selectable pressure level to an airway of a patient; monitoring a flow of the flow of breathing gas and outputting a flow signal indicative thereof;
determining a skewness of a patient's inspiratory waveforms from the flow signal; and controlling a pressure of the flow of breathing gas based on the skewness determination.
- 43. The method of claim 42, wherein determining the skewness of the inspiratory waveform includes:
segmenting the inspiratory waveform into a first region that corresponds to a beginning portion of the inspiratory waveform and a second region that corresponds to a middle portion of the inspiratory waveform; and comparing the flow in the second region to the flow in the first region.
- 44. The method of claim 43, further comprising determining an average of the highest rates of flow in the first region, and determining an average of the highest rates of flow in the second region, and wherein the comparing step includes comparing the average of the highest rates of flow in the first region with the average of the highest rates of flow in the second region.
- 45. The method of claim 43, wherein the first region corresponds to approximately a first third of the inspiratory waveform and the second region corresponds to approximately a second third of the inspiratory waveform, and wherein the highest flow rates in the first region and the second region are defined as the flow rates within 5% of the highest flow rates in each region.
- 46. The method of claim 43, wherein the comparing step includes determining the skewness as a skewness number as follows:
- 47. The method of claim 46, wherein controlling the pressure of the flow of breathing gas includes increasing the pressure responsive to a decrease in the skewness number.
- 48. An auto-titration pressure support system comprising:
a pressure generating system adapted to generate a flow of breathing gas at a selectable pressure level; a patient circuit having a first end adapted to be coupled to the pressure generating system and a second end adapted to be coupled to an airway of a patient; a monitoring system associated with the patient circuit or the pressure generating system and adapted to measure a parameter indicative of a flow of gas in such a patient's airway and to output a flow signal indicative thereof, and a controller coupled to the monitoring system and the pressure generating system, for controlling the pressure generating system based on the output of the monitoring system, wherein the controller is programmed determine whether the patient is experiencing a central apnea/hypopnea or an obstructive/restrictive apnea/hypopnea by monitoring one or more of the following: (1) at least one shape parameter associated with the flow of gas during an apnea/hypopnea period, and (2) a characteristic of the flow of gas at the end of the apnea/hypopnea period indicative of an increase in respiratory effort.
- 49. The system of claim 48, wherein the shape parameters monitored by the controller during an apnea/hypopnea period include a flatness of an inspiratory portion of a flow waveform, a roundness of the inspiratory portion of the flow waveform, a skewness of the inspiratory portion of the flow waveform.
- 50. The system of claim 49, wherein the controller considers a patient to be experiencing an obstructive/restrictive apnea/hypopnea responsive to the inspiratory portion of the flow waveform exhibiting at least one of an increase in flatness, a decrease in roundness, and an increased skewness, otherwise the controller considers the patient to be experiencing a central apnea/hypopnea, and wherein the controller prevents a pressure increase by the pressure generating system responsive to a determination that the patient is experiencing a central apnea/hypopnea.
- 51. The system of claim 48, wherein the characteristic of the flow of gas at the end of the apnea/hypopnea period is a volume or a peak flow related characteristic, wherein the controller considers a patient to be experiencing an obstructive/restrictive apnea/hypopnea responsive to the volume or the peak flow related characteristic at the end of the apnea/hypopnea period exceeding a predetermined threshold, otherwise the controller considers the patient to be experiencing a central apnea/hypopnea, and wherein the controller prevents a pressure increases by the pressure generating system responsive to a determination that the patient is experiencing a central apnea/hypopnea.
- 52. A method or providing pressure support system to a patient, comprising:
providing flow of breathing gas at a selectable pressure level to an airway of a patient; monitoring a flow of the flow of breathing gas and outputting a flow signal indicative thereof; and determining whether the patient is experiencing a central apnea/hypopnea or an obstructive/restrictive apnea/hypopnea by monitoring one or more of the following: (1) at least one shape parameter associated with the flow of gas during an apnea/hypopnea period, and (2) a characteristic of the flow of gas at the end of the apnea/hypopnea period indicative of an increase in respiratory effort; and controlling a pressure of the flow of breathing gas based on the skewness determination.
- 53. The method of claim 52, wherein the shape parameters monitored by the controller during an apnea/hypopnea period include a flatness of an inspiratory portion of a flow waveform, a roundness of the inspiratory portion of the flow waveform, a skewness of the inspiratory portion of the flow waveform.
- 54. The method of claim 53, the determining step includes considering a patient to be experiencing an obstructive/restrictive apnea/hypopnea responsive to the inspiratory portion of the flow waveform exhibiting at least one of an increase in flatness, a decrease in roundness, and an increased skewness, otherwise considering the patient to be experiencing a central apnea/hypopnea, and wherein the pressure controlling step includes preventing a pressure increase responsive to a determination that the patient is experiencing a central apnea/hypopnea.
- 55. The method of claim 52, wherein the characteristic of the flow of gas at the end of the apnea/hypopnea period is a volume or a peak flow related characteristic, wherein the determining step includes considering a patient to be experiencing an obstructive/restrictive apnea/hypopnea responsive to the volume or the peak flow related characteristic at the end of the apnea/hypopnea period exceeding a predetermined threshold, otherwise considering the patient to be experiencing a central apnea/hypopnea, and wherein the pressure controlling step includes preventing a pressure increase responsive to a determination that the patient is experiencing a central apnea/hypopnea.
- 56. An auto-titration pressure support system comprising:
a pressure generating system adapted to generate a flow of breathing gas at a selectable pressure level; a patient circuit having a first end adapted to be coupled to the pressure generating system and a second end adapted to be coupled to an airway of a patient; a monitoring system associated with the patient circuit or the pressure generating system and adapted to measure a parameter indicative of a pressure at a patient's airway, a flow of gas in such a patient's airway, or both and to output a pressure signal, a flow signal indicative thereof, respectively, or both; and a controller coupled to the monitoring system and the pressure generating system, for controlling the pressure generating system based on the output of the monitoring system, wherein the controller is programmed to:
(1) determine whether the patient is experiencing an apnea/hypopnea based on the pressure signal or the flow signal, (2) set a pressure treatment limit based on a pressure at a time an apnea/hypopnea is detected, (3) cause the pressure generating system to increase a pressure of the flow of breathing gas delivered to a patient responsive to a current pressure being below the pressure treatment limit, and (4) cause the pressure generating system to decrease a pressure of the flow of breathing gas delivered to a patient responsive to a current pressure being at or above the pressure treatment limit.
- 57. A method of providing pressure support to a patient, comprising:
providing flow of breathing gas at a selectable pressure level to an airway of a patient; monitoring a pressure, a flow, or both of the flow of breathing gas and outputting a pressure signal, a flow signal indicative thereof, respectively, or both; determine whether the patient is experiencing an apnea/hypopnea based on the pressure signal, the flow signal, or both; setting a pressure treatment limit based on a pressure at a time an apnea/hypopnea is detected; increasing a pressure of the flow of breathing gas delivered to a patient responsive to a current pressure being below the pressure treatment limit; and decreasing a pressure of the flow of breathing gas delivered to a patient responsive to a current pressure being at or above the pressure treatment limit.
CROSS-REFRENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. § 119(e) from U.S. provisional patent application No. 60/329,250 filed Oct. 12, 2001 and U.S. provisional patent application No. 60/331,838 filed Nov. 20, 2001 the contents of which are incorporated herein by reference.
Provisional Applications (2)
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Number |
Date |
Country |
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60329250 |
Oct 2001 |
US |
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60331838 |
Nov 2001 |
US |