WO2000045882A1 - Technique de stablisation ventilatoire - Google Patents

Technique de stablisation ventilatoire Download PDF

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Publication number
WO2000045882A1
WO2000045882A1 PCT/US2000/002848 US0002848W WO0045882A1 WO 2000045882 A1 WO2000045882 A1 WO 2000045882A1 US 0002848 W US0002848 W US 0002848W WO 0045882 A1 WO0045882 A1 WO 0045882A1
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WO
WIPO (PCT)
Prior art keywords
mask
tube
gas
flow
patient
Prior art date
Application number
PCT/US2000/002848
Other languages
English (en)
Inventor
John E. Remmers
Eric Andrew Hajduk
Ronald Scott Platt
Original Assignee
Remmers John E
Eric Andrew Hajduk
Ronald Scott Platt
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Remmers John E, Eric Andrew Hajduk, Ronald Scott Platt filed Critical Remmers John E
Priority to AU28689/00A priority Critical patent/AU2868900A/en
Priority to EP00907143A priority patent/EP1156845A1/fr
Priority to CA2362177A priority patent/CA2362177C/fr
Publication of WO2000045882A1 publication Critical patent/WO2000045882A1/fr

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/0057—Pumps therefor
    • A61M16/0066—Blowers or centrifugal pumps
    • A61M16/0069—Blowers or centrifugal pumps the speed thereof being controlled by respiratory parameters, e.g. by inhalation
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/021—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes operated by electrical means
    • A61M16/022—Control means therefor
    • A61M16/024—Control means therefor including calculation means, e.g. using a processor
    • A61M16/026—Control means therefor including calculation means, e.g. using a processor 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
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/08—Bellows; Connecting tubes ; Water traps; Patient circuits
    • A61M16/0816—Joints or connectors
    • A61M16/0841—Joints or connectors for sampling
    • A61M16/085—Gas sampling
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/0045—Means for re-breathing exhaled gases, e.g. for hyperventilation treatment
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/0003—Accessories therefor, e.g. sensors, vibrators, negative pressure
    • A61M2016/003—Accessories therefor, e.g. sensors, vibrators, negative pressure with a flowmeter
    • A61M2016/0033—Accessories therefor, e.g. sensors, vibrators, negative pressure with a flowmeter electrical
    • A61M2016/0036—Accessories therefor, e.g. sensors, vibrators, negative pressure with a flowmeter electrical in the breathing tube and used in both inspiratory and expiratory phase
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/0003—Accessories therefor, e.g. sensors, vibrators, negative pressure
    • A61M2016/003—Accessories therefor, e.g. sensors, vibrators, negative pressure with a flowmeter
    • A61M2016/0033—Accessories therefor, e.g. sensors, vibrators, negative pressure with a flowmeter electrical
    • A61M2016/0042—Accessories therefor, e.g. sensors, vibrators, negative pressure with a flowmeter electrical in the expiratory circuit
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/10—Preparation of respiratory gases or vapours
    • A61M16/1005—Preparation of respiratory gases or vapours with O2 features or with parameter measurement
    • A61M2016/102—Measuring a parameter of the content of the delivered gas
    • A61M2016/103—Measuring a parameter of the content of the delivered gas the CO2 concentration
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M2230/00—Measuring parameters of the user
    • A61M2230/40—Respiratory characteristics
    • A61M2230/43—Composition of exhalation
    • A61M2230/432—Composition of exhalation partial CO2 pressure (P-CO2)

Definitions

  • Central sleep apnea is a type of sleep-disordered breathing that is characterized by a failure of the sleeping brain to generate regular, rhythmic bursts of neural activity.
  • apnea represents a disorder of the respiratory control system responsible for regulating the rate and depth of breathing, i.e. overall pulmonary ventilation.
  • Central sleep apnea should be contrasted with obstructive sleep apnea, where the proximate cause of apnea is obstruction of the pharyngeal airway despite ongoing rhythmic neural outflow to the respiratory muscles.
  • the difference between central sleep apnea and obstructive sleep apnea is clearly established, and the two can co-exist. While central sleep apnea can occur in a number of clinical settings, it is most commonly observed in association with heart failure or cerebral vascular insufficiency.
  • An example of central sleep apnea is Cheyne-Stokes respiration.
  • the respiratory control system comprises a negative feedback system wherein a central pattern generator creates rhythmic bursts of activity when respiratory chemo- receptors sensing carbon dioxide, oxygen and pH are adequately stimulated (Fig. 1). While this neural output of the brainstem central pattern generator to the respiratory muscles derives from a neural rhythm generated intrinsically by the central pattern generator, the generator becomes silent if the feedback signals, related to arterial P C02 and P 02 , are not sufficiently intense. In other words, the respiratory rhythm is generated by a conditional central pattern generator which requires an adequate input stimulus derived from peripheral chemoreceptors sensing arterial P C02 and P 02 from central chemoreceptors sensing brain P C02 /pH.
  • the intensity of neural activity generated by the respiratory central pattern generator depends directly upon the arterial P C02 inversely on the arterial P 02 .
  • the central and peripheral chemoreflex loops constitute a negative feedback system regulating the arterial P 02 and P C02 , holding them constant within narrow limits (Fig. 1).
  • This normal regulation of arterial blood gases is accomplished by a stable ventilatory output of the respiratory central pattern generator.
  • central sleep apnea represents an instability of the respiratory control system. The instability can arise from one of two mechanisms, namely: (1) intrinsic failure of the respiratory central pattern generator in the face of adequate stimulation by respiratory chemoreceptors; or (2) lack of adequate stimulation of the central pattern generator by respiratory chemoreceptors.
  • the former is referred to as the "intrinsic instability” and the latter is referred to as the “chemoreflex instability. " Theoretically, both mechanisms can co-exist. The common form of central sleep apnea is thought to be caused by the chemoreflex instability mechanism.
  • the chemoreflex control of breathing might exhibit instability either because the delay of the negative feedback signal is excessively long or because the gain of the system is excessively high.
  • Current evidence indicates that the latter constitutes the principal derangement in central sleep apnea caused by heart failure.
  • the overall response of the control system to a change in arterial P C02 is three-fold higher in heart-failure patients with central sleep apnea than in those having no sleep-disordered breathing.
  • This increased gain probably resides within the central chemoreflex loop; however, high gain of the peripheral chemoreflex loop cannot be excluded. Accordingly, the fundamental mechanism of central sleep apnea is taken to be high loop gain of the control system, which results in feedback instability during sleep.
  • Central sleep apnea causes repeated arousals and oxyhemoglobin desaturations. Although firm evidence linking central sleep apnea to morbidity and mortality is lacking, a variety of evidence leads to the inference that central sleep apnea may promote cardiac arhythmias, strokes, or myocardial infarctions. The repeated nocturnal arousals are likely to impair daytime cognitive function and quality of life.
  • the present invention is a method for varying the efficiency of pulmonary gas exchange by using a controlled amount of rebreathing during certain periods of the central sleep apnea respiration cycle so as to counteract the effects of the transient excessive ventilation on the level of carbon dioxide and oxygen in the lungs and in the arterial blood.
  • this strategy is an attempt to stabilize breathing by minimizing oscillations in the feedback variables.
  • the invention counteracts periodic breathing due to central sleep apnea by decreasing loop gain of the respiratory control system.
  • the invention dynamically modulates efficiency of pulmonary gas exchange in relation to pulmonary ventilation.
  • pulmonary ventilation is stable at resting values, the performance of the system is unchanged.
  • the system is made more inefficient, thus decreasing loop gain and stabilizing the system.
  • Rebreathing can be used to increase the inspired percentage carbon dioxide and reduce the inspired percentage oxygen just before or during the period of overbreathing.
  • the patient's ventilation is continuously monitored and analyzed in real time so that the ventilation periodicities of the central sleep apnea breathing can be detected and the inspired carbon dioxide and oxygen concentrations adjusted appropriately by varying the amount of exhaled gas that is reinspired.
  • a rebreathing apparatus is a part of a nasal continuous positive airway pressure (CPAP) system.
  • CPAP nasal continuous positive airway pressure
  • the use of continuous positive airway pressure may have a beneficial effect on cardiac function in patients with congestive heart failure. In the future it is likely that patients with congestive heart failure will receive nasal CPAP for treatment of the heart failure.
  • Central sleep apnea may not immediately disappear upon administration of conventional nasal CPAP therapy as central sleep apnea respiration is basically of a non-obstructive origin. However, over a period of about four weeks the degree of heart failure improves; thus, the resulting central sleep apnea respiration may be relieved by the continuous positive airway pressure. This is described in the papers, Naughton, et al., "Effective Continuous Positive Airway Pressure on Central Sleep Apnea and Nocturnal Percentage Carbon Dioxide in Heart Failure," American Journal Respiratory Critical
  • a conventional CPAP system is modified in one embodiment of the present invention to allow a controlled amount of rebreathing during a portion of the central sleep apnea respiration cycle.
  • a valve is used to control the amount of rebreathing. When the valve is closed, rebreathing occurs and when the valve is open no rebreathing occurs.
  • a computer connected to a flow meter can be used to detect periodicities in the central sleep apnea respiration cycle. The computer can then control the valve to open and close.
  • FIG. 1 Another embodiment of the present invention concerns a passive low-bias-flow device for treating central sleep apnea.
  • This apparatus includes a gas-supply means, such as a blower, and a mask that is fitted on a patient's face.
  • the gas-supply means is adjusted so that air flow from the gas-supply means is such that for the patient's normal breathing, the gas flow supplied by the gas-supply means is sufficient to prevent a significant amount of the patient's exhaled gases from flowing retrograde into a tube between the gas-supply means and the mask.
  • the preset air flow is such that some of the patient's exhaled gases flow retrograde into the tube.
  • Yet another embodiment of the present invention is a method for adjusting an apparatus comprising a gas-supply means, a mask and a tube between the mask and the gas-supply means.
  • the mask is fitted to the patient's face.
  • the supply of gas from the gas-supply means is set high enough that during the patient's normal breathing, the gas flow supplied by the gas-supply means is sufficient to prevent a significant amount of the patient's exhaled gases from flowing retrograde into the tube, but set low enough that during periods of increased breathing increased with central sleep apnea, some of the patient's exhaled gases flow retrograde into the tube.
  • Still another embodiment of the present invention concerns an apparatus for treating central sleep apnea wherein the supply of gas from a gas-supply means has a varying gas pressure that changes at different times during the patient's sleep cycle.
  • the gas pressure from the blower is decreased during periods of increased breathing associated with central sleep apnea so that some of the patient's exhaled gases flow retrograde between the mask and the blower.
  • This approach is less advantageous because users often find the varying mask pressure to be annoying.
  • varying of the mask pressure can affect the internal dead space in a manner counter to the rebreathing effect.
  • blower pressure is set at a minimum level that eliminates all evidence of upper airway obstruction, or at a level deemed appropriate for treating heart failure.
  • the bias flow is then reduced to a level that eliminates central sleep apnea without increasing the external dead space during unstimulated breathing.
  • the bias flow can then be fixed at this level or varied systematically within or between cycles of periodic breathing.
  • FIG. 1 is a diagram illustrating central sleep apnea.
  • Fig. 2 is a diagram illustrating one embodiment of the rebreathing apparatus of the present invention.
  • Fig. 3 is a diagram illustrating central sleep apnea respiration.
  • Fig. 4 A is a diagram of one embodiment of the present invention using a passive loop gain modulation for ventilization stabilization using a single pre-set gas flow pressure from a blower.
  • Fig. 4B is a diagram of an alternate embodiment of the system of Fig. 4 A using a flow meter and a computer.
  • Fig. 5 is a diagram of one embodiment of the present invention which uses computer control of the blower pressure to modify the vent pressure from the blower during certain periods of a sleep cycle.
  • Fig. 6 is a diagram of an embodiment of the present invention which uses computer control of a dead space attached to valves so as to cause rebreathing during certain periods of a sleep cycle.
  • Fig. 7 is a diagram of one embodiment of the present invention using a recirculator to increase rebreathing during certain periods of a sleep cycle.
  • Figs. 8 A - 8F are diagrams depicting air flow accorded in tubing connecting between the blower and the nose mask.
  • Fig. 9 depicts the changes in V ret and V wash that occur when pulmonary ventilation is stimulated by increasing arterial P C02 .
  • Figs. 10, 11 and 12 are diagrams that illustrate the dependence of V ret , V ED and T FRA C on V E .
  • Fig. 13 is a diagram that illustrates the relationship of V A and V E at the four levels of V B
  • Fig. 14 is a diagram illustrating the general dependence of the loop gain on the ratio log V E /V A .
  • Fig. 15 is a diagram that illustrates the breathing air flow in the tube of a conventional CPAP system
  • Fig. 16 is a diagram that illustrates the normal breathing flow in the tube of the embodiment of Fig. 4A.
  • Fig. 17 is a diagram that illustrates overbreathing flow in the tube in the embodiment of Fig. 4A.
  • Fig. 18A is a diagram of an embodiment of the present invention in which the size of the exit tube of the mask is varied slowly over the patient's sleep cycle.
  • Fig. 18B is a graph illustrating one example of changing of the exit hole size during the night, for the apparatus of Fig. 18A.
  • Fig. 19 is a diagram of an alternate embodiment using the blower output as an active control device to adjust the level of rebreathing by a patient.
  • FIG. 2 is a diagram illustrating the rebreathing apparatus of one active control embodiment of the present invention.
  • a continuous positive airway pressure apparatus including blower 20, tube 22 and mask 24 is used.
  • Mask 24 preferably produces an airtight tight seal to the face for use in the continuous positive airway pressure treatment.
  • U.S. Patent, 5,645,053, "Auto-CPAP Systems and Method for Preventing Patient Disturbance Using Airflow Profile Information."
  • a blower is used to maintain a relatively high constant pressure in a mask and to provide a bias flow of fresh air from the blower out the mask.
  • tube 26 is connected to the exhaust port 31 of the mask and conducts gas to the variable resistor 28.
  • the valve can be located on the exhaust port of the mask.
  • Tube 22 is used as a dead space for rebreathing during some periods of the central sleep apnea respiration.
  • valve 28 When the valve 28 is open, no rebreathing occurs because all the exhaled gas is carried out tube 26 through valve 28 by the bias flow before inspiration occurs. When valve 28 is closed, the bias flow ceases and no expired air is conducted through tube 26. In this case, some partial rebreathing occurs because the expired air is conducted retrograde up tube 22 to the blower.
  • the gases in the tube 26 have a higher concentration of carbon dioxide and a lower concentration of oxygen than room air.
  • the bias flow of gas from the blower through the mask and out port 30 would be adequate to completely purge the system during the expiratory phase of the respiratory cycle so that no gas expired by the patient remains in the system.
  • the gas inspired by the patient had a composition of room air (O j concentration 21 %; CO 2 concentration about 0%).
  • the bias flow is reduced to zero by completely occluding port 30 with valve 28, the gas exhaled by the patient would fill the tube 22 connecting the mask to the blower.
  • expired gas would typically have a carbon dioxide concentration of 5% and an oxygen concentration of 16% .
  • the patient Upon inhalation, the patient would first inspire the high carbon dioxide, low oxygen mixture filling the tube, followed by inhalation of room air from the blower.
  • flow meter 32 connected to computer 34 is used to detect the flow of gases to and from the blower 20.
  • the computer 34 is used to identify the periodicities in pulmonary ventilation caused by the central sleep apnea respiration and to control the valve 28 to cause rebreathing during certain periods of the central sleep apnea cycle.
  • the gas flow from the blower comprises the bias flow (mask exit flow + leak flow) plus the respiratory airflow.
  • the computer monitors this flow and calculates the bias flow, leak flow, retrograde flow, retrograde expired volume and wash volume.
  • a computer 34 can detect the amplitude of the central sleep apnea cycle and to adjust the resistance of the valve 28 according. For example, if there are large variations in pulmonary ventilation during the central sleep apnea cycle, the valve 28 can be completely closed during the overbreathing period. If there are small variations in pulmonary ventilation during the central sleep apnea cycle, the valve 28 can be partially open during the overbreathing period. Thus, a higher level of rebreathing will occur when the variation in pulmonary ventilation during the central sleep apnea cycle is high than will occur when the variation in pulmonary ventilation during the central sleep apnea cycle is low. Because of the low impedance of the CPAP blower 20, variations of the resistance in the outflow line cause very little change in mask pressure. Accordingly, the full range of variations in outflow resistance can be made without producing significant deviations in the desired CPAP mask pressure.
  • the flow meter 32 and computer 34 can quantitate the level of pulmonary ventilation. For example, the ratio of breath volume to breath period gives an indication of the level of the instantaneous pulmonary ventilation. Other indices such as mean or peak inspiratory flow rate could also be used.
  • Fig. 3 shows an idealized diagram of the periodicities of the overbreathing and underbreathing during central sleep apnea respiration.
  • This diagram shows the regions of overbreathing 50a and the regions of underbreathing 50b compared to the moving time average of ventilation.
  • the computer system will be able to determine the periodicities of the central sleep apnea breathing.
  • a number of techniques are used to control the degree and timing of rebreathing with the valve 28 in order to eliminate central sleep apnea.
  • One way of controlling rebreathing so as to reduce the central sleep apnea respiration is to anticipate the different cycles in the central sleep apnea respiration. For example, looking at Fig. 3, at time A, the system will anticipate a period of overbreathing and thus begin rebreathing by closing valve 28 as shown in Fig. 2. By the time overbreathing portion
  • the apparatus of the present invention can reduce central sleep apnea rebreathing (line 50) to a lower level as shown in dotted line 60 in Fig. 2.
  • Time A and time B for the beginning and end of the rebreathing can be determined by the computer 34 shown in Fig. 2.
  • FIG. 4A is a diagram that illustrates a passive loop gain modulation system for use in the present invention.
  • Figure 4A depicts a system using a gas-supply means such as the air blower 60 connected to a length of input tubing 62 and then to a mask 64. This system uses a simple fixed exit port for the mask.
  • a tubing volume greater than that normally used with obstructive sleep apnea can be used with the present invention.
  • the blower 60 preferably has a very low impedance. That is, changes in the air flow do not significantly change the air pressure supplied by the blower. This can help maintain a relatively stable mask pressure even as the tube flow becomes retrograde. Additionally, in one embodiment, the air blower is able to supply air pressure much lower than conventional CPAP blowers. In one embodiment, the air blower can be adjusted to supply pressures below 4cm H 2 O (preferably 2cm H 2 O or below). The ability to supply such small pressures allows for the retrograde flow as discussed below. The mask is fitted about the patient's nose.
  • the air supplied from the blower 60 and tube 62 to the mask 64 does not cause any rebreathing because any exhaled air will be flushed before the next inhale period.
  • the preset gas flow pressure is set so that enough exhaled air flows retrograde into the tube such that during the next inhale period some expired gas is rebreathed.
  • the overbreathing occurs during certain periods of the sleep cycle associated with central sleep apnea. Rebreathing during periods of overbreathing during central sleep apnea tends to reduce the resulting spike in the blood oxygen level. Thus, the period of underbreathing following the overbreathing in the central sleep apnea sleep cycle will also be reduced.
  • the alternating periods of under- and overbreathing are reduced by the rebreathing which takes place during the periods of overbreathing.
  • the rebreathing attenuates the arterial blood oxygen spike and the reduction in arterial P C02 caused by the overbreathing.
  • the amplitude of the periodic breathing is reduced.
  • the embodiment of Fig. 4 A is different than the conventional CPAP in that the preset gas flow pressure is lower and/or the mask exit hole is smaller than that used with conventional CPAP systems.
  • the system of Fig. 4 A has the advantage that it does not require active control of the blower pressure.
  • the patient can be checked into a sleep center and the correct blower pressure and mask exit hole size set. Thereafter, the system can be placed on the patient's nose every night without requiring an expensive controller-based system.
  • the preset blower gas pressure depends upon the air flow resistance caused by the exit 64, the normal exhale pressure and the overbreathing exhale pressure. If the gas- supply pressure system is an air blower 60, then by modifying the revolutions per minute of the air blower, the preset gas flow pressure can be set.
  • the air supply pressure for patients with central sleep apnea but without obstructive sleep apnea can be set at a relatively low level such as below 4cm HO.
  • the normal mask exit holes produce the desired effect at these pressures.
  • the end-tidal F C02 and inspired F C02 can be monitored by a CO 2 meter 65 with an aspiration line connected to the mask.
  • all mouth leaks should be eliminated in order to have expired gas move into the tubing 62. This can be achieved by applying a chin strap, or by using a full arch dental appliance applied to the upper and lower teeth, or both.
  • An alternative approach to difficult mouth leaks is to use a full face mask covering the mouth as well as the nose. This means that expired gas emanating from the nose or the mouth will travel retrogradely up the tubing 62 toward the blower.
  • the mask pressure is increased progressively until all evidence of upper airway obstruction is eliminated. If the patient is receiving nasal CPAP as treatment for heart failure, mask pressure is set at the desired level (typically 8- 10cm H 2 O). The bias flow (mask hole size) can then be reduced until central sleep apnea is eliminating without adding dead space. For patients with heart conditions, the mask pressure can be set at the valve suggested by the literature (typically about 10cm H 2 O). Then the bias flow is adjusted. The flow through tube 62 depends upon the difference in pressure between the blower pressure (i.e. , pressure at the outlet of the blower) and mask pressure.
  • Blower pressure is set by the revolutions per minute (RPM) of the blower and will be virtually constant because the internal impedance of the blower is very low.
  • RPM revolutions per minute
  • mask pressure is less than blower pressure by an amount that is dictated by the flow resistive properties of the connecting tube and the rate of bias flow. This is typically l-2cm of water pressure difference when bias flow is at 0.5-1.5L/sec.
  • mask pressure varies during the respiratory cycle depending upon the flow resistance properties of the connecting tube and the airflow generated by the patient.
  • inspiration the mask pressure drops, typically 1-2 cm of water, an during expiration pressure may rise transiently a similar amount.
  • the peak-to-peak fluctuations in mask pressure are less than during heavy breathing or hyperpnea.
  • the mask pressure rises during exhalation and this reduces the driving pressure difference between the blower and the mask, thereby reducing flow in the tube. If the expired tidal volume increases, however, peak expiratory flow will increase and this will be associated with a further increase in mask pressure. If mask pressure increases to equal blower pressure, flow in the tube will stop. When mask pressure exceeds blower pressure, flow in the tube will be in a retrograde direction, i.e., from the mask to the blower. Such retrograde airflow will first occur early in expiration and the volume of air which moves into the connecting tube will be washed out later in expiration as mask pressure declines and flow from the blower to the mask increases.
  • Figs. 15-17 illustrate the flow in the tube between a blower and a mask.
  • Fig. 15 is a graph that illustrates breathing air flow in the tube of a conventional CPAP system.
  • Figs. 16 and 17 are diagrams that illustrate the effect of breathing in systems of the present invention in which the blower pressure and bias flow out of the exit hole of the mask are set such that there is retrograde flow during portions of overbreathing associated with central sleep apnea.
  • Fig. 16 illustrates the situation in which there is normal breathing. Even with normal breathing, there is some retrograde flow during the period 202. Later in the exhale period the retrograde volume is washed from the tube by the normal flow that occurs during period 204. Thus there is little or no rebreathing during the normal breathing periods.
  • the system of the present invention does not add dead space during the normal breathing periods. This is important because the addition of dead space can increase the concentration of carbon dioxide that is supplied to the bloodstream. It is assumed that if the increased carbon dioxide level persists for multiple days, the body will readjust the internal feedback system an undesirable manner.
  • Fig. 17 illustrates an embodiment showing overbreathing along with the apparatus of the present invention.
  • the overbreathing is such that there is some retrograde flow of exhaled gases, which remain in the tube at the time of the next inhale portion. This means that at the next inhale portion, the patient will reinspire some exhaled gases with the resultant higher concentration of carbon dioxide.
  • the initial exhale region 206 is greater than the exhale region 208.
  • the retrograde flow volume and wash volume for the normal breathing can be used to set the operation of the present invention.
  • the retrograde volume region 202 should be one -half the size of the wash flow region 204 for normal breathing.
  • Other rules of thumb such as the comparisons of the aveolar ventilation to the bias flow out of the mask and/or comparisons of the washout time to the duration of expiration could also be used to set the operations of the system of the present invention.
  • Fig. 4B shows the device of Fig. 4A with the addition of a computer 67 and flow meter 69. The flow meter 69 is used to detect the desired air flow in the tube 62.
  • the blower can then be adjusted so that there is retrograde flow during periods of overbreathing and no retrograde flow otherwise.
  • the device of Fig. 4B can be used to calibrate the device of Fig. 4 A for an individual patient.
  • Figs. 18A and 18B illustrate an embodiment in which the mask exit size is slowly changed over the course of the night.
  • the blower 210 supplies airflow at a selected pressure.
  • Flowmeter 212 is connected into the tube 214 which allows the flow in the tube 214 to be determined along with additional parameters of the system including the aveolar volume, bias flow, and the like.
  • the processor 216 slowly changes the size of the exit hole using the variable air resistance apparatus 218. Unlike the system of Fig. 2, the size of the variable output resistance 218 is modified slowly over the night.
  • the output valve can be set relatively large, increasing the bias flow out of the mask and thus reducing any effect of retrograde into the tube 214.
  • the valve diameter can be slowly decreased, which can cause an increase of retrograde flow into the tube 214 during the overbreathing portion of central sleep apnea and thus can cause rebreathing which can reduce the central sleep apnea. Additional adjustments in the mask valve opening can be made based upon calculations made by the processor 216.
  • Fig. 5 is an embodiment of the present invention in which the blower 70 is dynamically controlled.
  • a flow meter 72 is placed in the tube 74 between the blower 70 and mask 76.
  • a flow meter can also be placed near the patient's nose.
  • the system of Fig. 5 allows computer control to decrease the blower pressure during certain periods of a sleep cycle. Thus, during periods of heavy breathing, the blower pressure can be reduced to facilitate retrograde flow and rebreathing. This embodiment is less advantageoous because of the mixed effects of changes in the mask pressure.
  • the retrograde flow into the tube 74 can be increased and decreased, as desired.
  • Fig. 6 is an alternate embodiment of the present invention.
  • the mask 82 is connected to dead space 84 by computer-controlled valves 86 and 88.
  • the amount of rebreathing during certain period of the sleep cycle can be modified by changing bias flow by opening and closing the valves 86 and 88, thus reducing the central sleep apnea.
  • Fig. 7 is an embodiment using a recirculator 90.
  • the recirculator 90 allowing exhaled air to be drawn in by the recirculator
  • the central sleep apnea can be reduced by increasing the rebreathing at selected portions of the sleep cycle.
  • One embodiment of the invention is applied in the setting of nasal continuous positive pressure (CPAP) therapy.
  • the loop gain of the negative feedback respiratory control system is reduced principally by increasing the volume of external dead space (V ED ).
  • V ED external dead space
  • the external dead space constitutes an extension of the internal dead space (V ID ) comprising the airways of the lung and the upper airway.
  • V ID internal dead space
  • V D V D
  • V D V ED + V ID (Equation 1)
  • This volume represents an obligatory inefficiency of the control system in that it reduces the portion of the tidal volume (V ⁇ ) that participates in gas exchange within the lungs.
  • V ⁇ the portion of the tidal volume that participates in gas exchange within the lungs.
  • the tidal volume is the sum of two components
  • V n + V ⁇ (Equation 2)
  • V A represents the "alveolar" portion of the tidal volume, i.e. the volume that participates in respiratory gas exchange.
  • V E V A + V D , where the symbols N E , V A , and V D signify the products f.V T , f.V A and f.V D (f represents respiratory frequency).
  • V E represents the output of the respiratory central pattern generator and V A is a variable which influences arterial blood gas pressures.
  • the link between V E and V A is, of course, V D which is the primary variable manipulated in dynamically controlling loop gain.
  • Dynamic control of the rebreathing volume is achieved when the patient is breathing through a nasal CPAP apparatus.
  • the nose When using conventional nasal CPAP the nose is covered by a mask which is connected to a pressure-generating source by a length of tubing. The nose mask is flushed continuously by a stream of gas flowing from the pressure source and exiting the exhaust port of the mask. This will be referred to as the bias flow (V B ).
  • V B bias flow
  • the rate of exhaust flow is relatively high so that virtually all the expired gas which enters the mask from the nose flows into the mask and out the exhaust port. Because of the relatively high V B the mask is completely washed out before the next inspiration occurs.
  • the nose mask adds no external dead space.
  • the invention dynamically increases V ED by using a lower value of V B and this, in turn, dynamically reduces V A (Equation 2).
  • V A the component of pulmonary ventilation effective in gas exchange, alveolar ventilation (V A )
  • V A determines the values of the feedback variables, arterial P 02 and P C02
  • V D directly influences loop gain (Fig. 1).
  • loop gain (L.G.) of the system can be manipulated as below:
  • the increase in V ED occurs only during periods of hyperpnea, as described below.
  • the invention utilizes changes in CPAP pressure to change lung volume and, thereby, influence loop gain of the respiratory control system.
  • increase in lung volume decreases loop gain by decreasing the dynamic change in feedback variables (arterial P C02 and P 02 ) when alveolar ventilation changes dynamically.
  • cardiac P C02 and P 02 the dynamic change in feedback variables
  • an increase in lung volume decreases the end-expiratory length of inspiratory muscles, thereby decreasing their force generation during inspiration.
  • both effects of nasal CPAP decrease the loop gain.
  • the nose mask is replaced with a full face mask.
  • the nose mask is connected to a positive pressure outlet of a low impedance blower by a tubing, in one embodiment typically 2-3cm in diameter and 1.5m long.
  • the bias flow exits the mask either through an orifice of fixed, selectable size ( Figures 4A, 4B, 5, 6, 7) or through a tubing, in one embodiment (1.5m long, 1cm in diameter) connected to a computer- controlled variable resistor ( Figure 2).
  • the mask pressure is determined by blower RPM
  • the rate of bias flow V B is the resultant of mask pressure and mask outflow resistance.
  • the apparatus shown in Figs. 2 and 4B includes a pneumotachagraph for measuring flow from the blower.
  • This device is suitable for initial titration or for nightly therapeutic use. Also, a CO 2 meter can be added with a sampling catheter connected to the mask. This allows monitoring of end-tidal and inspired F C02 .
  • the device shown in Fig. 4 A is a simpler version of that shown in Fig. 4B and is suitable for nightly use.
  • the dynamically variable bias flow device (Fig. 2) allows moment-to-moment adjustment of bias flow with negligible changes in mask pressure.
  • the exhaust resistor can be controlled by an independent observer during a polysomnographic study, or it can be automatically controlled by a computer algorithm.
  • the control of external dead space volume (V ED ) is either passively adjusted with the exhaust resistance being constant, or actively adjusted with exhaust resistance being varied in time.
  • Fig. 8 depicts airflow recorded in the tubing which connects the blower to the nose mask. Positive values signify airflow from the blower to the mask, and negative values indicate airflow from the mask to the blower.
  • the former is referred to as "wash” airflow since it eliminates expired gas from the mask; the latter is referred to as "retrograde” airflow since it represents expired air flowing in the reverse direction to that which normally occurs during CPAP administration.
  • Fig. 8 A top panel
  • airflow in the tubing is equal to the sum of two air flows, V B and respiratory airflow.
  • Figs. 8A, 8B, 8C, 8D, 8E and 8F depict the changes in tubing airflow that occur as V B is progressively reduced from l.OL/sec (Fig. 8A) to 0.15L/sec (Fig. 8F).
  • V B Respiratory airflow is held constant throughout.
  • V B is reduced from 1.0 to 0.5, 0.35, 0.25, 0.20 and 0.15L/sec (Figs. 8A, 8B, 8C, 8D, 8E, 8F)
  • V ret The volume of air which moves retrogradely during expiration
  • V wash the volume of air which moves from the blower to the mask during expiration
  • V R residual volume
  • V R can be estimated as the difference between V RET - V WASH .
  • V R V RET - V WASH (Equation 4)
  • V RET would increase and V R would become positive.
  • T e the duration of expiration
  • V WASH would decrease and V R would become positive.
  • V B is relatively low (0.35 and 0.25 in this example)
  • chemical stimulation will cause V R to assume a positive value so that higher levels of pulmonary ventilation will be associated with greater values of V R .
  • V R The presence of a positive value for V R indicates that V ED will assume a finite value (Fig. 8F). However, V R does not equal V ED .
  • gas resident in the mask and tubing flows to one of two places, namely: out the exhaust port or into the respiratory tract. Only the latter constitutes V ED . Accordingly, a fraction of V R will be inspired, that fraction depending on the value of V B relative to the inspiratory flow rate. Use of a high value of V B will minimize V ED .
  • chemical stimulation of breathing causes three changes in the respiratory pattern, an increase in expiratory air flow rate, a decrease in Te, and an increase in inspiratory air flow rate, each of which acts independently to augment V ED .
  • FIG. 8B illustrates the time in expiration when the tubing and mask are flushed by fresh, room air. This time is expressed as a fraction of T e and referred to as T FRAC .
  • T FRAC increases progressively as V B decreases.
  • T FRAC equals 100% , a critical value of V B has been reached; further decreases in V B will produce a finite value of V ED .
  • V ED V R - (V B )(t ) (Equation 5)
  • V ED can be calculated by progressively incrementing inspiratory time (t) from zero (the onset of inspiration) and calculating
  • V SUM inspired volume plus exhaust port volume i.e. ,
  • Vj represents inspiratory flow rate, i.e., total flow minus bias flow during inspiration.
  • V SUM represents inspiratory flow rate, i.e., total flow minus bias flow during inspiration.
  • Fig. 9 depicts the changes in V RET and V ED that occur when pulmonary ventilation is stimulated by increasing arterial P C02 .
  • V B is assumed to equal 0.25L/sec in all cases, and is approximately two times resting V A (5.7L/min).
  • Further stimulation of breathing (Fig. 9B) results in V ED equal to 0.47L when V E equals 19.5L/sec, V ED equal to 0.79L when V E equals 25.7L/sec (Fig. 9C) and V ED equal to 1.19L when V E equals 36.7L/sec (Fig. 9D).
  • T FRAC increases progressively as V E increases for a constant V B .
  • V RET V ED
  • T FRAC T FRAC
  • Figs. 10, 11 and 12 The dependence of V RET , V ED and T FRAC on V E is shown in Figs. 10, 11 and 12, respectively, for all four values of V E .
  • Each plot shows a family of V B isopleths.
  • an d T FRAC show a quasi-linear increase as V E increases (Figs. 10, 11, 12 and 13).
  • Fig. 13 illustrates the relationship between V A and V E at the five levels of V B .
  • V E For values of l.OL/sec and greater, all points lie on a monotonically ascending curve. However, for lower values of V B , the relationship is shifted downward, indicating that an increment in V E caused by an increase in chemical stimulus will cause a smaller increment in V A . This implies a reduction in loop gain which can be quantitated as the change in slope of this relationship. Note that at values of V E equal to 0.35L/sec less, V A becomes constant for values of V E greater than 15L/sec. In other words, the invention clamps V A at some maximal value.
  • Fig. 14 illustrates the overall dependence of loop gain on the ratio, log V E /V A .
  • This ratio calculated for resting breathing, provides a normalized index of V E for any patient.
  • the relationship is plotted over the range of log V E /V A from 0 to 1., i.e. over the range of variation in V E where V ED is less than zero under resting conditions.
  • the loop gain decreases steeply as resting V RET /V WASH decreases from 0.5 to 0.
  • V B is approximately two times V A and T FRAC equals 80% .
  • V D is dynamically adjusted in keeping with variations in V E such that the periodic fluctuation in V A is attenuated. This means that fluctuations in arterial P 02 and P co2 are reduced, so that loop gain of the system is reduced. This acts to stabilize breathing.
  • the advantage of the passively adjusting dead space device is that loop gain can be reduced by a relatively simple apparatus requiring no active algorithmic, dynamic adjustment in V B . Once the effective V B has been determined, this can be achieved by permanent adjustment of the resistance of the exhaust port of the mask, thereby eliminating the need for an exhaust tubing and computer-controlled exhaust resistor. However, if the loop gain of the patient's respiratory control system is very high, the passive apparatus may not reduce the loop gain sufficiently to stabilize breathing. In that case, a dynamically adjusting V ED apparatus is employed. In the embodiment that dynamically adjusts V B , the indicator variables (V RET , V WASH , T frac and V B /V A ) are calculated on line.
  • Periodic breathing is detected either by the recurrence of apneas or by autoregressive analysis.
  • Fig. 19 depicts another embodiment of the invention.
  • the patient with central sleep apnea wears a nose mask or full face mask 220 which can be loose fitting.
  • the mask 220 is purged by a bias flow from a high-impedance blower 222 which supplies a constant rate of airflow to the mask.
  • This bias flow is selectable and rapidly adjustable by the controlling computer 224.
  • the bias flow exits to the atmosphere through a low- resistance reservoir tubing 226.
  • the respiratory airflow both inspiration and expiration
  • the mask pressure remains near atmospheric pressure.
  • a pneumotachograph (flow meter 228) in the reservoir tubing allows monitoring of bias flow and respiration airflow and calculation of wash volume during expiration and expired tidal volume.
  • bias flow is held relatively high so that wash voluke exceds the volume of gas expired into the tube. Accordingly, when inspiration begins, the reservoir tube has been washed completely with bias flow, and the patient inspires room air. Thus, no external dead space has been added when the patient is breathing normally and no ventilatory periodicity is detected by the computer.
  • the computer 222 detects ventilatory periodicity, bias flow is varied in synchrony with the periodicity. Specifically, when instantaneous ventilation is greater thant he moving average, bias flow is reduced so that wash volume is less than expired tidal volume. This causes rebreathing and decreases loop gain of the system.
  • bias flow is maintained at high values so that no rebreathing occurs.
  • the volume of gas resident in the reservoir tubing 226 at the end of expiration i.e. , the rebreathing volume
  • the volume of gas resident in the reservoir tubing 226 at the end of expiration is calculated on line and is adjusted to be proportional to the difference between instantaneous ventilation and moving average ventilation.
  • dead space increases progressively as overbreathing occurs, thereby minimizing the effect of the excessive ventilation on arterial blood gases. This, in turn, minimizes the duration of the apnea or magnitude of hypopnea that follows the overbreathing and stabilizes ventilation.

Abstract

L'invention concerne un système de réduction de l'apnée du sommeil, dans lequel on utilise plusieurs procédés permettant d'augmenter la réinhalation d'un patient au cours de périodes du cycle de sommeil. La sur-oxygénation, qui résulte généralement de la période d'hyperventilation, peut être réduite, réduisant ainsi la période d'insuffisance respiratoire correspondante et réduisant également de façon efficace le gain de boucle associé à l'apnée du sommeil. Un mode de réalisation comprend un ventilateur (60), un masque (64) pourvue d'une sortie de gaz (66), un tube (62) reliant le ventilateur au masque.
PCT/US2000/002848 1999-02-04 2000-02-04 Technique de stablisation ventilatoire WO2000045882A1 (fr)

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AU28689/00A AU2868900A (en) 1999-02-04 2000-02-04 Ventilatory stablization technology
EP00907143A EP1156845A1 (fr) 1999-02-04 2000-02-04 Technique de stablisation ventilatoire
CA2362177A CA2362177C (fr) 1999-02-04 2000-02-04 Technique de stablisation ventilatoire

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EP1328305A2 (fr) * 2000-09-25 2003-07-23 Respironics Inc. Procede et dispositif destines a creer une pression positive et variable dans les voies aeriennes
WO2004069317A1 (fr) * 2003-01-28 2004-08-19 Beth Israel Deaconess Medical Center, Inc. Systemes a gaz et procedes pour permettre une stabilite respiratoire
EP1477199A1 (fr) * 2003-05-15 2004-11-17 Azienda Ospedaliera Pisana Appareil pour ventilation artificielle non invasive
WO2005070487A1 (fr) * 2004-01-23 2005-08-04 University Technologies International Inc. Technologie de stabilisation ventilatoire
AU2003277338B2 (en) * 2002-10-09 2008-06-05 Compumedics Limited Method and apparatus for maintaining and monitoring sleep quality during therapeutic treatments
EP1923088A3 (fr) * 2003-01-28 2008-12-03 Beth Israel Deaconess Medical Center, Inc. Systèmes de gaz et procédés permettant la stabilité respiratoire
EP2173249A1 (fr) * 2007-07-26 2010-04-14 UTI Limited Partnership Intervention transitoire destinée à modifier la respiration d'un patient
US7717110B2 (en) 2004-10-01 2010-05-18 Ric Investments, Llc Method and apparatus for treating Cheyne-Stokes respiration
US7900626B2 (en) 2006-04-17 2011-03-08 Daly Robert W Method and system for controlling breathing
WO2012127415A1 (fr) 2011-03-24 2012-09-27 Koninklijke Philips Electronics N.V. Procédés et systèmes pour gérer l'apnée du sommeil centrale en contrôlant le volume rétrograde cumulé
US8381732B2 (en) 2008-03-21 2013-02-26 The Periodic Breathing Foundation, Llc Nasal interface device
WO2013164733A1 (fr) * 2012-05-01 2013-11-07 Koninklijke Philips N.V. Système et procédé pour contrôler le flux pendant l'expiration dans un système d'assistance respiratoire
US9030304B2 (en) 2010-05-07 2015-05-12 Covidien Lp Ventilator-initiated prompt regarding auto-peep detection during ventilation of non-triggering patient
US9027552B2 (en) 2012-07-31 2015-05-12 Covidien Lp Ventilator-initiated prompt or setting regarding detection of asynchrony during ventilation
US9038633B2 (en) 2011-03-02 2015-05-26 Covidien Lp Ventilator-initiated prompt regarding high delivered tidal volume
CN112169130A (zh) * 2010-03-25 2021-01-05 瑞思迈巴黎股份有限公司 用于呼吸治疗装置的可呼吸气体进气口控制设备
WO2021136702A1 (fr) * 2019-12-31 2021-07-08 Koninklijke Philips N.V. Utilisation d'un gain de boucle pour une ventilation par pression positive des voies respiratoires

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US7073501B2 (en) 1999-02-04 2006-07-11 Univerity Technologies International Inc. Ventilatory stabilization technology
US7267122B2 (en) 2000-09-25 2007-09-11 Ric Investments, Llc Method and apparatus for providing variable positive airway pressure
EP1328305A2 (fr) * 2000-09-25 2003-07-23 Respironics Inc. Procede et dispositif destines a creer une pression positive et variable dans les voies aeriennes
EP1328305A4 (fr) * 2000-09-25 2007-07-25 Respironics Inc Procede et dispositif destines a creer une pression positive et variable dans les voies aeriennes
AU2003277338B2 (en) * 2002-10-09 2008-06-05 Compumedics Limited Method and apparatus for maintaining and monitoring sleep quality during therapeutic treatments
US7886740B2 (en) 2003-01-28 2011-02-15 Beth Israel Deaconess Medical Center, Inc. Gas systems and methods for enabling respiratory stability
WO2004069317A1 (fr) * 2003-01-28 2004-08-19 Beth Israel Deaconess Medical Center, Inc. Systemes a gaz et procedes pour permettre une stabilite respiratoire
EP1923088A3 (fr) * 2003-01-28 2008-12-03 Beth Israel Deaconess Medical Center, Inc. Systèmes de gaz et procédés permettant la stabilité respiratoire
AU2003291817B2 (en) * 2003-01-28 2007-02-15 Beth Israel Deaconess Medical Center, Inc. Gas systems and methods for enabling respiratory stability
WO2004101049A1 (fr) * 2003-05-15 2004-11-25 Azienda Ospedaliera Pisana Appareil de ventilation mecanique non effractif
EA008202B1 (ru) * 2003-05-15 2007-04-27 Азиенда Оспедалиера Пизана Устройство для неинвазивной механической вентиляции
JP2007500562A (ja) * 2003-05-15 2007-01-18 アツィエンダ・オスペダリエラ・ピサナ 非侵襲性の人口呼吸のための装置
US8240307B2 (en) 2003-05-15 2012-08-14 Azienda Ospedaliera Pisana Apparatus for non-invasive mechanical ventilation
EP1477199A1 (fr) * 2003-05-15 2004-11-17 Azienda Ospedaliera Pisana Appareil pour ventilation artificielle non invasive
AU2005205851B2 (en) * 2004-01-23 2011-08-11 Uti Limited Partnership Ventilatory stabilization technology
JP2007518497A (ja) * 2004-01-23 2007-07-12 ユニヴァーシティ・テクノロジーズ・インターナショナル・インコーポレーテッド 換気安定化技術
EP1706164A4 (fr) * 2004-01-23 2011-04-20 Uti Limited Partnership Technologie de stabilisation ventilatoire
EP1706164A1 (fr) * 2004-01-23 2006-10-04 University Technologies International Inc. Technologie de stabilisation ventilatoire
JP2011235123A (ja) * 2004-01-23 2011-11-24 Uti Lp 換気安定化技術
WO2005070487A1 (fr) * 2004-01-23 2005-08-04 University Technologies International Inc. Technologie de stabilisation ventilatoire
US8220456B2 (en) 2004-10-01 2012-07-17 Ric Investments, Llc Method and apparatus for treating cheyne-stokes respiration
US7717110B2 (en) 2004-10-01 2010-05-18 Ric Investments, Llc Method and apparatus for treating Cheyne-Stokes respiration
US8695595B2 (en) 2004-10-01 2014-04-15 Ric Investments, Llc Method and apparatus for treating Cheyne-Stokes respiration
US8485181B2 (en) 2006-04-17 2013-07-16 The Periodic Breathing Foundation, Llc Method and system for controlling breathing
US8074646B2 (en) 2006-04-17 2011-12-13 Daly Robert W Method and system for controlling breathing
US7900626B2 (en) 2006-04-17 2011-03-08 Daly Robert W Method and system for controlling breathing
EP2173249A1 (fr) * 2007-07-26 2010-04-14 UTI Limited Partnership Intervention transitoire destinée à modifier la respiration d'un patient
EP2173249A4 (fr) * 2007-07-26 2013-07-24 Uti Limited Partnership Intervention transitoire destinée à modifier la respiration d'un patient
US8381732B2 (en) 2008-03-21 2013-02-26 The Periodic Breathing Foundation, Llc Nasal interface device
CN112169130B (zh) * 2010-03-25 2023-11-21 瑞思迈巴黎股份有限公司 用于呼吸治疗装置的可呼吸气体进气口控制设备
US11717637B2 (en) 2010-03-25 2023-08-08 Resmed Paris Sas Breathable gas inlet control device for respiratory treatment apparatus
CN112169130A (zh) * 2010-03-25 2021-01-05 瑞思迈巴黎股份有限公司 用于呼吸治疗装置的可呼吸气体进气口控制设备
US9030304B2 (en) 2010-05-07 2015-05-12 Covidien Lp Ventilator-initiated prompt regarding auto-peep detection during ventilation of non-triggering patient
US9038633B2 (en) 2011-03-02 2015-05-26 Covidien Lp Ventilator-initiated prompt regarding high delivered tidal volume
US10500357B2 (en) 2011-03-24 2019-12-10 Koninklijke Philips N.V. Methods and systems to manage central sleep apnea by controlling accumulated retrograde volume
CN103458950A (zh) * 2011-03-24 2013-12-18 皇家飞利浦有限公司 通过控制累积逆行体积来管理中枢性睡眠呼吸暂停的方法和系统
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US10166360B2 (en) 2012-05-01 2019-01-01 Koninklijke Philips N.V. System and method for controlling flow during exhalation in a respiratory support system
WO2013164733A1 (fr) * 2012-05-01 2013-11-07 Koninklijke Philips N.V. Système et procédé pour contrôler le flux pendant l'expiration dans un système d'assistance respiratoire
US9027552B2 (en) 2012-07-31 2015-05-12 Covidien Lp Ventilator-initiated prompt or setting regarding detection of asynchrony during ventilation
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