Methods and systems for an optimized proportional assist ventilation

Information

  • Patent Grant
  • 9993604
  • Patent Number
    9,993,604
  • Date Filed
    Friday, April 27, 2012
    13 years ago
  • Date Issued
    Tuesday, June 12, 2018
    6 years ago
Abstract
This disclosure describes systems and methods for providing an optimized proportional assist breath type during ventilation of a patient. The disclosure describes a novel breath type that delivers a target airway pressure calculated based on a desired patient effort range to a triggering patient.
Description
INTRODUCTION

Medical ventilator systems have long been used to provide ventilatory and supplemental oxygen support to patients. These ventilators typically comprise a source of pressurized oxygen which is fluidly connected to the patient through a conduit or tubing. As each patient may require a different ventilation strategy, modern ventilators can be customized for the particular needs of an individual patient. For example, several different ventilator modes or settings have been created to provide better ventilation for patients in various different scenarios.


Optimized Proportional Assist Ventilation

This disclosure describes systems and methods for providing an optimized proportional assist breath type during ventilation of a patient. The disclosure describes a novel breath type that delivers a target airway pressure calculated based on a desired patient effort range to a triggering patient.


In part, this disclosure describes a method for ventilating a patient with a ventilator. The method includes:


a) retrieving a desired patient effort range;


b) estimating an initial percent support setting based on the desired patient effort range;


c) calculating a target airway pressure based at least on the initial percent support setting; and


d) delivering the target airway pressure to a patient.


Yet another aspect of this disclosure describes a ventilator system that includes: a pressure generating system; a ventilation tubing system; one or more sensors; a support module; and an OPA module. The pressure generating system is adapted to generate a flow of breathing gas. The ventilation tubing system includes a patient interface for connecting the pressure generating system to a patient. The one or more sensors are operatively coupled to at least one of the pressure generating system, the patient, and the ventilation tubing system. The one or more sensors generate output indicative of the inspiration flow. The support module estimates an initial percent support setting based at least on a desired patient effort range and calculates at least one adjusted percent support setting based at least on the desired patient effort range, and a current patient effort. The OPA module calculates an initial target airway pressure based at least on the initial percent support setting, calculates at least one adjusted target airway pressure based at least on an adjusted percent support setting, and utilizes the output indicative of the inspiration flow to determine a patient trigger for delivery of a breath to the patient.


The disclosure further describes a computer-readable medium having computer-executable instructions for performing a method for ventilating a patient with a ventilator. The method includes:


a) repeatedly retrieving a desired patient effort range;


b) estimating an initial percent support setting based on the desired patient effort range;


c) repeatedly calculating a target airway pressure based at least on the initial percent support setting; and


d) repeatedly delivering the target airway pressure to a patient.


The disclosure also describes a ventilator system including means for retrieving a desired patient effort range, means for estimating an initial percent support setting based on the desired patient effort range, means for calculating a target airway pressure based at least on the initial percent support setting, and means for delivering the target airway pressure to a patient.


These and various other features as well as advantages which characterize the systems and methods described herein will be apparent from a reading of the following detailed description and a review of the associated drawings. Additional features are set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the technology. The benefits and features of the technology will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.


It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.





BRIEF DESCRIPTION OF THE DRAWINGS

The following drawing figures, which form a part of this application, are illustrative of embodiments of systems and methods described below and are not meant to limit the scope of the invention in any manner, which scope shall be based on the claims appended hereto.



FIG. 1 illustrates an embodiment of a ventilator.



FIG. 2A illustrates an embodiment of a method for ventilating a patient on a ventilator during a first breath in an optimized proportional assist breath type.



FIG. 2B illustrates an embodiment of a method for ventilating a patient on a ventilator during any breath after a first delivered breath in an optimized proportional assist breath type.



FIG. 3 illustrates an embodiment of method for ventilating a patient on a ventilator based on a desired treatment metric range during an optimized proportional assist breath type.





DETAILED DESCRIPTION

Although the techniques introduced above and discussed in detail below may be implemented for a variety of medical devices, the present disclosure will discuss the implementation of these techniques in the context of a medical ventilator for use in providing ventilation support to a human patient. A person of skill in the art will understand that the technology described in the context of a medical ventilator for human patients could be adapted for use with other systems such as ventilators for non-human patients and general gas transport systems.


Medical ventilators are used to provide a breathing gas to a patient who may otherwise be unable to breathe sufficiently. In modern medical facilities, pressurized air and oxygen sources are often available from wall outlets. Accordingly, ventilators may provide pressure regulating valves (or regulators) connected to centralized sources of pressurized air and pressurized oxygen. The regulating valves function to regulate flow so that respiratory gas having a desired concentration of oxygen is supplied to the patient at desired pressures and rates. Ventilators capable of operating independently of external sources of pressurized air are also available.


While operating a ventilator, it is desirable to control the percentage of oxygen in the gas supplied by the ventilator to the patient. Further, as each patient may require a different ventilation strategy, modern ventilators can be customized for the particular needs of an individual patient. For example, several different ventilator breath types have been created to provide better ventilation for patients in various different scenarios.


Effort-based breath types, such as proportional assist (PA) ventilation, dynamically determine the amount of ventilatory support to deliver based on a continuous estimation/calculation of patient effort and respiratory characteristics. The resulting dynamically generated profile is computed in real- or quasi-real-time and used by the ventilator as a set of points for control of applicable parameters.


Initiation and execution of an effort-based breath, such as PA, has two operation prerequisites: (1) detection of an inspiratory trigger; and (2) detection and measurement of an appreciable amount of patient respiratory effort to constitute a sufficient reference above a ventilator's control signal error deadband. Advanced, sophisticated triggering technologies detect initiation of inspiratory efforts efficiently. In ventilation design, patient effort may be represented by the estimated inspiratory muscle pressure (patient effort) and is calculated based on measured patient inspiration flow. Patient effort is utilized to calculate a target airway pressure for the inspiration. The target airway pressure as used herein is the airway pressure measured at the ventilator-patient interface and is calculated on an on-going basis using patient effort according to the equation of motion. In other words, the target airway pressure is the amount of pressure delivered by the ventilator to the patient.


A PA breath type refers to a type of ventilation in which the ventilator acts as an inspiratory amplifier that provides pressure support based on the patient's effort. The degree of amplification (the “percent support setting”) during a PA breath type is set by an operator, for example as a percentage based on the patient's effort. In one implementation of a PA breath type, the ventilator may continuously monitor the patient's instantaneous inspiratory flow and instantaneous net lung volume, which are indicators of the patient's inspiratory effort. These signals, together with ongoing estimates of the patient's lung compliance and lung/airway resistance and the Equation of Motion (Target Pressure(t)=Ep∫Qpdt+QpRp−Patient Effort(t)), allow the ventilator to estimate/calculate a patient effort and derive therefrom a target airway pressure to provide the support that assists the patient's inspiratory muscles to the degree selected by the operator as the percent support setting. Qp is the instantaneous flow inhaled by the patient, and Ep and RQ are the patient's respiratory elastance and resistance, respectively. In this equation the patient effort is inspiratory muscle pressure and is negative. The percent support setting input by the operator divides the total work of breathing calculated between the patient and the ventilator as shown in the equations below:

Patient Effort(t)=(1.0−k)[Ep∫Qpdt+QpRp];  1) and
Target Airway Pressure(t)=k[Ep∫Qpdt+QpRp].  2)

Patient Effort(t) is the amount of pressure provided by the patient at a time t, Target airway pressure(t) is the amount of pressure provided by the ventilator at the time t, total support ([Ep∫Qpdt+QpRp]) is the sum of contributions by the patient and ventilator, and k is the percent support setting (percentage of total support to be contributed by the ventilator) input by the operator.


During PA breath types, the percent support setting is input by the operator of the ventilator and does not vary. Clinicians, typically, do not utilize a percent support setting unless operating a PA breath type. Accordingly, often times, clinicians or ventilator operators are unfamiliar with a percent support setting and need additional training to learn how to use a proportional assist breath type appropriately. Further, during the previously utilized PA breath types, the patient effort was only estimated/calculated. The ventilator did not attempt to control or change the amount of effort exerted by the patient. Accordingly, the patient could exert too much effort resulting in fatigue from over-loading or the patient could exert too little effort leading to muscle atrophy from non-use.


Researchers have discovered that maintaining a desired patient effort can provide the patient with several benefits. For example, certain patient efforts prevent muscle atrophy from non-use while at the same time prevent muscle fatigue from over-loading. Further, controlling and/or adjusting a patient's effort can also help to maintain a desired treatment metric range.


Accordingly, the current disclosure describes an optimized proportional assist (OPA) breath type for ventilating a patient. The OPA breath type is similar to the PA breath type except that the OPA breath type delivers a target airway pressure to the patient calculated based on a desired patient effort range for a triggering patient instead of being based on an input percent support setting. Accordingly, the ventilator estimates an initial percent support setting during the OPA breath type in an attempt to achieve a patient effort in the desired range. The target airway pressure delivered to the patient is calculated based on the estimated initial percent support setting. After the delivery of the target airway pressure based on the estimated initial percent support setting, the ventilator periodically calculates/estimates the actual amount of patient effort or the current patient effort exerted by the patient. The ventilator compares the current patient effort to the desired patient effort range. If the current the patient effort is not within the desired patient effort range, the ventilator modifies the percent support setting in an attempt to deliver a target airway pressure that will cause the patient to exert a patient effort in the desired patient effort range in the next breath. In some embodiments, the desired patient effort range is input or selected by the operator of the ventilator. Most clinicians are familiar with patient effort levels. Accordingly, an OPA breath type requires minimal training or education for proper use by clinicians. Further, the OPA breath type allows clinicians to better manage the patient's contribution to the total work of breathing.


Additionally, in some embodiments, the ventilator during the OPA breath type may determine the desired patient effort range based on a desired treatment metric range. The desired treatment metric range (e.g., a rapid shallow breathing index (RSBI) range) is input or selected by the operator. In these embodiments, the percent support setting is adjusted until the current patient effort is maintained within the desired patient effort range for at least two consecutive breaths. Once the current patient effort is maintained within the desired patient effort range, one or more ventilator parameters (e.g., positive end expiratory pressure (PEEP), rise time, and oxygen percentage) and/or their derivatives (e.g., windowed history, trends, windowed statistics, rate of change with respect to other factors, and etc.) are adjusted until the current treatment metric and/or their derivatives (e.g., windowed history, trends, windowed statistics, rate of change with respect to other factors, and etc.) is within the desired treatment metric range.


As used herein, patient parameters are any parameters determined based on measurements taken of the patient, such as heart rate, respiration rate, a blood oxygen level (SpO2), inspiratory lung flow, airway pressure, and etc. As used herein, ventilator parameters are parameters that are determined by the ventilator and/or are input into the ventilator by an operator, such as a breath type, desired patient effort, and etc. Some parameters may be either ventilator and/or patient parameters depending upon whether or not they are input into the ventilator by an operator or determined by the ventilator. Accordingly, the treatment metric is a ventilator parameter.


The percent support setting and the ventilator parameters are adjusted based on algorithms and optimization programming techniques to provide advisory input and/or automatic adjustments to ventilation parameters (e.g., percent support in OPA) and/or a timed changes in ventilation modality (patient-triggered or ventilator-driven breath delivery) to increase the efficiency and confidence in the predictive nature of the desired treatment metric range. In other words, the algorithms and optimization programming techniques adjust the percent support setting and one or more ventilator parameters in an attempt to get the current treatment metric within the desired treatment metric range.



FIG. 1 is a diagram illustrating an embodiment of an exemplary ventilator 100 connected to a human patient 150. Ventilator 100 includes a pneumatic system 102 (also referred to as a pressure generating system 102) for circulating breathing gases to and from patient 150 via the ventilation tubing system 130, which couples the patient 150 to the pneumatic system 102 via an invasive (e.g., endotracheal tube, as shown) or a non-invasive (e.g., nasal mask) patient interface 180.


Ventilation tubing system 130 (or patient circuit 130) may be a two-limb (shown) or a one-limb circuit for carrying gases to and from the patient 150. In a two-limb embodiment, a fitting, typically referred to as a “wye-fitting” 170, may be provided to couple a patient interface 180 (as shown, an endotracheal tube) to an inspiratory limb 132 and an expiratory limb 134 of the ventilation tubing system 130.


Pneumatic system 102 may be configured in a variety of ways. In the present example, pneumatic system 102 includes an expiratory module 108 coupled with the expiratory limb 134 and an inspiratory module 104 coupled with the inspiratory limb 132. Compressor 106 or other source(s) of pressurized gases (e.g., air, oxygen, and/or helium) is coupled with inspiratory module 104 and the expiratory module 108 to provide a gas source for ventilatory support via inspiratory limb 132.


The inspiratory module 104 is configured to deliver gases to the patient 150 according to prescribed ventilatory settings. In some embodiments, inspiratory module 104 is configured to provide ventilation according to various breath types, e.g., via volume-control, pressure-control, OPA, or via any other suitable breath types.


The expiratory module 108 is configured to release gases from the patient's lungs according to prescribed ventilatory settings. Specifically, expiratory module 108 is associated with and/or controls an expiratory valve for releasing gases from the patient 150.


The ventilator 100 may also include one or more sensors 107 communicatively coupled to ventilator 100. The sensors 107 may be located in the pneumatic system 102, ventilation tubing system 130, and/or on the patient 150. The embodiment of FIG. 1 illustrates a sensor 107 in pneumatic system 102.


Sensors 107 may communicate with various components of ventilator 100, e.g., pneumatic system 102, other sensors 107, processor 116, support module 117, OPA module 118, and any other suitable components and/or modules. In one embodiment, sensors 107 generate output and send this output to pneumatic system 102, other sensors 107, processor 116, support module 117, OPA module 118, treatment module 119 and any other suitable components and/or modules. Sensors 107 may employ any suitable sensory or derivative technique for monitoring one or more patient parameters or ventilator parameters associated with the ventilation of a patient 150. Sensors 107 may detect changes in patient parameters indicative of patient triggering, for example. Sensors 107 may be placed in any suitable location, e.g., within the ventilatory circuitry or other devices communicatively coupled to the ventilator 100. Further, sensors 107 may be placed in any suitable internal location, such as, within the ventilatory circuitry or within components or modules of ventilator 100. For example, sensors 107 may be coupled to the inspiratory and/or expiratory modules for detecting changes in, for example, circuit pressure and/or flow. In other examples, sensors 107 may be affixed to the ventilatory tubing or may be embedded in the tubing itself. According to some embodiments, sensors 107 may be provided at or near the lungs (or diaphragm) for detecting a pressure in the lungs. Additionally or alternatively, sensors 107 may be affixed or embedded in or near wye-fitting 170 and/or patient interface 180. Indeed, any sensory device useful for monitoring changes in measurable parameters during ventilatory treatment may be employed in accordance with embodiments described herein.


As should be appreciated, with reference to the Equation of Motion, ventilatory parameters are highly interrelated and, according to embodiments, may be either directly or indirectly monitored. That is, parameters may be directly monitored by one or more sensors 107, as described above, or may be indirectly monitored or estimated/calculated using a model, such as a model derived from the Equation of Motion (e.g., Target Airway Pressure(t)=Ep∫Qpdt+QpRp−Patient Effort(t)).


The pneumatic system 102 may include a variety of other components, including mixing modules, valves, tubing, accumulators, filters, etc. Controller 110 is operatively coupled with pneumatic system 102, signal measurement and acquisition systems, and an operator interface 120 that may enable an operator to interact with the ventilator 100 (e.g., change ventilator settings, select operational modes, view monitored parameters, etc.).


In one embodiment, the operator interface 120 of the ventilator 100 includes a display 122 communicatively coupled to ventilator 100. Display 122 provides various input screens, for receiving clinician input, and various display screens, for presenting useful information to the clinician. In one embodiment, the display 122 is configured to include a graphical user interface (GUI). The GUI may be an interactive display, e.g., a touch-sensitive screen or otherwise, and may provide various windows and elements for receiving input and interface command operations. Alternatively, other suitable means of communication with the ventilator 100 may be provided, for instance by a wheel, keyboard, mouse, or other suitable interactive device. Thus, operator interface 120 may accept commands and input through display 122. Display 122 may also provide useful information in the form of various ventilatory data regarding the physical condition of a patient 150. The useful information may be derived by the ventilator 100, based on data collected by a processor 116, and the useful information may be displayed to the clinician in the form of graphs, wave representations, pie graphs, text, or other suitable forms of graphic display. For example, patient data may be displayed on the GUI and/or display 122. Additionally or alternatively, patient data may be communicated to a remote monitoring system coupled via any suitable means to the ventilator 100. In one embodiment, the display 122 may display one or more of a current patient effort, a desired patient effort range, a desired treatment metric range, a current treatment metric, a RSBI, SpO2, a mouth pressures measured at 100 milliseconds (ms) after the onset of inspiratory effort (P100), a tidal volume, a volumetric carbon dioxide (VCO2), a respiratory rate, a spontaneous inspiration to expiration ratio (I:E) volume, a minute volume, an initial percent support setting, and an adjusted percent support setting.


Controller 110 may include memory 112, one or more processors 116, storage 114, and/or other components of the type commonly found in command and control computing devices. Controller 110 may further include a support module 117, an OPA module 118, and treatment module 119 configured to deliver gases to the patient 150 according to prescribed breath types as illustrated in FIG. 1. In alternative embodiments, the support module 117, the OPA module 118, and the treatment module 119 may be located in other components of the ventilator 100, such as the pressure generating system 102 (also known as the pneumatic system 102).


The memory 112 includes non-transitory, computer-readable storage media that stores software that is executed by the processor 116 and which controls the operation of the ventilator 100. In an embodiment, the memory 112 includes one or more solid-state storage devices such as flash memory chips. In an alternative embodiment, the memory 112 may be mass storage connected to the processor 116 through a mass storage controller (not shown) and a communications bus (not shown). Although the description of computer-readable media contained herein refers to a solid-state storage, it should be appreciated by those skilled in the art that computer-readable storage media can be any available media that can be accessed by the processor 116. That is, computer-readable storage media includes non-transitory, volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules or other data. For example, computer-readable storage media includes RAM, ROM, EPROM, EEPROM, flash memory or other solid state memory technology, CD-ROM, DVD, or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by the computer.


The inspiratory module 104 receives a breath type from the OPA module 118. The OPA module 118 receives a percent support setting for the breath type from the support module 117. In some embodiments, the OPA module 118 and/or the support module 117 are part of the controller 110 as illustrated in FIG. 1. In other embodiments, the OPA module 118 and/or the support module 117 are part of the processor 116, pneumatic system 102, and/or a separate computing device in communication with the ventilator 100.


Initiation and execution of an OPA breath type has two operation prerequisites: (1) detection of an inspiratory trigger; and (2) determining and commanding target airway pressures to be delivered to the patient 150 during inspiration. A patient trigger is calculated based on a measured or monitored patient inspiration flow. Any suitable type of triggering detection for determining a patient trigger may be utilized by the ventilator 100, such as nasal detection, diaphragm detection, and/or brain signal detection. Further, the ventilator 100 may detect patient triggering via a pressure-monitoring method, a flow-monitoring method, direct or indirect measurement of neuromuscular signals, or any other suitable method. Sensors 107 suitable for this detection may include any suitable sensing device as known by a person of skill in the art for a ventilator.


According to an embodiment, a pressure-triggering method may involve the ventilator 100 monitoring the circuit pressure, and detecting a slight drop in circuit pressure. The slight drop in circuit pressure may indicate that the patient's respiratory muscles are creating a slight negative pressure that in turn generates a pressure gradient between the patient's lungs and the airway opening in an effort to inspire. The ventilator 100 may interpret the slight drop in circuit pressure as a patient trigger and may consequently initiate inspiration by delivering respiratory gases.


Alternatively, the ventilator 100 may detect a flow-triggered event. Specifically, the ventilator 100 may monitor the circuit flow, as described above. If the ventilator 100 detects a slight drop in the base flow through the exhalation module during exhalation, this may indicate, again, that the patient 150 is attempting to inspire. In this case, the ventilator 100 is detecting a drop in bias flow (or baseline flow) attributable to a slight redirection of gases into the patient's lungs (in response to a slightly negative pressure gradient as discussed above). Bias flow refers to a constant flow existing in the circuit during exhalation that enables the ventilator 100 to detect expiratory flow changes and patient triggering.


The OPA module 118 sends an OPA breath type to the inspiratory module 104. The OPA breath type refers to a type of ventilation in which the ventilator 100 acts as an inspiratory amplifier that provides pressure support to the patient. The degree of amplification (the “percent support setting”) is determined by the support module 117 based on a retrieved desired patient effort range. The percent support setting determines how much support is provided by the ventilator 100. For example, if the percent support setting is 30%, then the ventilator provides a total pressure to the patient of which 70% is due to the patient effort (generation of muscle pressure) and the remaining 30% is due to the ventilator work, as estimated from the instantaneous flow or other monitored parameters based on the patient effort model used.


In an embodiment, the OPA breath type determines a target airway pressure by utilizing the percent support setting and the following equation:

Target Airway Pressure(t)=k[Ep∫Qpdt+QpRp]

The percent support setting (k) is held constant over one breath. Every computational cycle (e.g., 5 milliseconds, 10 milliseconds, etc.), the ventilator calculates a target airway pressure, based on the received percent support setting from the support module 117.


The OPA module 118 begins inspiratory assist when a trigger is detected and/or when the at least one monitored parameter is detected by the OPA module 118. However, if the patient ceases triggering inspiration, the assist also ceases. Accordingly, in some embodiments, the OPA module 118 includes a safety feature that has the ventilator 100 deliver a breath to the patient or switches the breath type to a non-spontaneous breath type if a patient trigger is not detected for a set period of time or based on the occurrence of a set event. This safety feature ensures that if a patient stops triggering, the patient will not stop receiving ventilation by the medical ventilator.


The support module 117 retrieves a desired patient effort range for the OPA breath type. The desired patient effort range represents a desired parameter from the patient effort profile over each breath. The desired patient effort may be a maximum, mean, root mean square (RMS), minimum or any other appropriate statistic of the a pressure waveform or patient muscle waveform during one or a window of multiple breaths. The desired patient effort range (such as a desired peak muscle pressure) may be retrieved from input or a selection by the operator of the ventilator 100 or may be retrieved from a determination made by the ventilator 100. The ventilator 100 may determine the desired patient effort range based on patient parameters and/or ventilator parameters. In some embodiments, the support module 117 receives the desired patient effort range from the treatment module 119, processor 116, and/or operator interface 120.


The desired patient effort range is a range of patient effort that should provide benefits to the patient. In some embodiments, the desired patient effort range prevents muscle atrophy from non-use while at the same time prevents muscle fatigue from over-loading. In further embodiments, determining a desired patient effort range based on a desired treatment metric range in combination with adjusting one or more ventilator parameters to maintain a current treatment metric in the desired treatment metric range to improve the ventilator's treatments of certain conditions, such as reducing the amount of time the ventilator takes to wean a patient from ventilation.


In some embodiments, the desired patient effort range is from about 5 cm H2O to about 10 cm of H2O. In other embodiments, the desired patient effort range is from about 4 cm H2O to about 12 cm of H2O. In some embodiments, the desired patient effort range is from about 6 cm H2O to about 9 cm of H2O. The desired patient effort range may include a solitary value. Accordingly, the desired patient effort range may be 5 cm of H2O, 6 cm of H2O, 7 cm of H2O, 8 cm of H2O, 9 cm of H2O, or 10 cm of H2O. These lists are not meant to be limiting. Any suitable patient effort range for improving the health of the patient may be utilized by the ventilator 100.


The support module 117 utilizes the retrieved desired patient effort range to estimate an initial percent support setting. The initial percent support setting as used herein is the percent support setting applied to at least the first breath delivered to the patient during execution of the OPA breath type. The support module 117 estimates the initial percent support setting, k, by utilizing the follow equation based on the equation of motion when given the other parameters:

Patient Effort(t)=(1.0−k)[Ep∫Qpdt+QpRp].

The ventilator utilizes an initial support setting and predetermined settings for the remaining parameters that cannot be determined since this is the first delivered breath. The predetermined settings may vary based on other parameters input by the clinician.


The support module 117 sends the initial percent support setting to the OPA module 118. As discussed above, the OPA module 118 then utilizes the initial percent support setting to calculate an initial target airway pressure to deliver to the patient 150. The OPA module 118 then causes the ventilator 100 to deliver the initial target airway pressure in at least the first breath provided to the patient during the utilization of the OPA breath type. Accordingly, the OPA module 118 may send the target airway pressure and/or instruction for delivering the target airway pressure to at least one of the processor 116, pneumatic system 102, inspiratory module 104 and/or the controller 110.


After the delivery of the first breath during the OPA breath type, the ventilator 100 calculates the current or actual patient effort exerted by the patient during the first breath and calculates the current patient effort periodically after the first delivered breath. Any component of the ventilator 100 may perform this step, such as the pneumatic system 102, controller 110, processor 116, support module 117, or OPA module 118. For example, the ventilator 100 may calculate the current patient effort for every delivered breath or every breath delivered after a predetermined amount of time or after a predetermined event. The current patient effort or actual patient effort as used herein represents the amount of patient effort exerted by the patient within the last computational cycle for the last delivered breath. The current patient effort is calculated based on the equation of motion and estimated patient parameters. The parameter representing the actual patient effort may be derived from the calculated patient effort profile over each breath. It may be defined as the maximum, mean, root mean square (RMS), or any other appropriate statistic of the actual muscle pressure waveform during one or a window of multiple breaths. The ventilator 100 estimates patient parameters based on the measurements directly or indirectly related to monitored patient parameters. In some embodiments, the estimated patient parameters include lung compliance (inverse of elastance) and/or lung/airway resistance. In further embodiments, the estimated lung compliance, lung elastance and/or lung/airway resistance are estimated based on monitored flow and/or the equation of motion. The estimated patient parameters may be estimated by any processor found in the ventilator 100. In some embodiments, the estimated patient parameters are calculated by the controller 110, the pneumatic system 102, and/or a separate computing device operatively connected to the ventilator 100.


In one embodiment, the support module 117 or any other suitable ventilator component compares the current patient effort with the desired patient effort range. If the support module 117 or any other suitable ventilator component determines that the actual or current patient effort is within the desired patient effort range, the support module 117 after receiving notification that or after determining that the current patient effort in within the desired patient effort range, sends the previously utilized percent support setting to the OPA module 118. In some instances, the previously utilized percent support setting may be the initial percent support setting. If the support module 117 or any other suitable ventilator component determines that the current patient effort is outside of the desired patient effort range, the support module 117 after receiving notification that or after determining that the current patient effort in not within the desired patient effort range, utilizes an optimization algorithm to adjust the percent support setting. Example optimization algorithms are listed below in the example section. The adjusted percent support setting (k) is held constant over one breath. The support module 117 sends the adjusted percent support setting to the OPA module 118. The OPA module 118, as discussed above, calculates the target airway pressure based on the percent support setting received from the support module 117, whether the percent support setting is an adjusted percent support setting, an initial percent support setting, and/or the previously utilized percent support setting. As discussed above, the target pressure is calculated every control cycle using the adjusted percent support setting by the ventilator 100.


Determining a desired patient effort based on desired treatment metric range can improve patient treatment, such as reducing weaning time and minimizing lung injury. A treatment metric is a ventilator parameter that is indicative of how well a patient treatment is going. In some embodiments, the treatment metric includes RSBI, SpO2, P100, oxygen index, end tidal carbon dioxide (ETCO2 or EtCO2), tidal volume, VCO2, respiratory rate, spontaneous I:E ratio, and a minute volume. The treatment module 119 receives a desired treatment metric range from the operator. The treatment module determines a desired patient effort range based on the received desired treatment metric range. The determined desired patient effort range is selected in attempt to help the patient achieve a current treatment metric within the desired treatment metric range. The treatment module sends the determined desired patient effort range to the appropriate ventilator component, such as the processor 116, support module 117 and/or the OPA module 118.


Once the ventilator 100 establishes a current patient effort within the desired patient effort range, the treatment module 119 determines if the current treatment metric is within the desired treatment metric range. The desired treatment metric range is a range of a ventilator parameter that improves the treatment of the patient. For example, if the treatment metric is RSBI, the desired treatment metric range may be a range of an RSBI of less than 105, which helps to decrease the amount of time a ventilator 100 takes to wean a patient 150 from ventilation. In some embodiments, the treatment metric range may not be a range and instead may be a solitary value, such as an RSBI of 100. The current treatment is metric as used herein represents the treatment metric as measured or determined by the ventilator 100 for the patient within the last computational cycle or for the last delivered breath depending upon the treatment metric utilized. In some embodiments, the treatment metric is derived from the calculated profiles over each breath. In some embodiments, the treatment metric is the maximum, mean, root mean square (RMS), or any other appropriate statistic of the waveform during one window or a window of multiple breaths.


In some embodiments, the treatment module 119 determines and adjusts the ventilator parameters and their derivatives based on weighted and/or trended desired treatment metric ranges input by the clinician. The treatment module 119 adjusts the percent support setting and the ventilator parameters by utilizing algorithms and optimization programming techniques to provide advisory input and/or automatic adjustments to ventilation parameters (e.g., oxygen percentage) and/or a timed changes in ventilation modality (patient-triggered or ventilator-driven breath delivery) to increase the efficiency and confidence in the predictive nature of the treatment success/failure indices. The ventilator parameters are adjusted based on treatment optimization algorithm. Example treatment optimization algorithms are listed below in the Example section. In other words, the algorithms and optimization programming techniques adjust the percent support setting and the one or more ventilator parameters in an attempt to improve patient treatment (i.e., maintain a current treatment metric within a desired treatment metric range).


The treatment module 119 sends the determined desired patient effort range to the support module 117. The support module 117 utilizes the determined desired patient effort range received from the treatment module 119 to calculate the percent support setting. The treatment module 119 sends the determined and/or adjusted one or more ventilator parameters to the appropriate component or components of the ventilator 100, such as the pneumatic system 102, controller 110, and/or processor 116, of the ventilator 100 for changing the one or more ventilator parameters.


In one embodiments, the treatment algorithm and/or optimization programming utilized by the treatment module 119 incorporates an internal model of the patient respiratory system in interaction with the ventilator 100 to address the relevant interactive dynamics between the patient 150 and the ventilator 100 as well as model and predict changes in patient's respiratory behavior and therapeutic outcome in response to the ongoing treatment protocol delivered by the ventilator 100. In some embodiments, the internal model for the treatment algorithm and/or optimization programming incorporates mechanisms for estimating system parameters (respiratory resistance, compliance, and etc.). Additionally, the treatment algorithm and/or the optimization programming utilized by the treatment module 119 may include features to estimate, model, or predict dynamics related to the functioning and interrelationships between inputs (e.g., percent support, SpO2, oxygen mix, and etc.) and output (generated patient effort over time). In further embodiments, the treatment algorithm includes mechanisms to estimate physiologic-based and/or hardware-based dynamics (transients, delays, and etc.).



FIGS. 2A and 2B illustrate an embodiment of a method 200 for ventilating a patient with a ventilator that utilizes an OPA breath type. FIG. 2A illustrates an embodiment of method 200A for ventilating a patient with a ventilator for the first breath delivered during the OPA breath type. FIG. 2B illustrates and embodiment of method 200B for ventilating a patient with a ventilator for every breath delivered after the first breath during the OPA breath type.


The OPA breath type delivers a target airway pressure calculated based on a desired patient effort range. The desired patient effort range allows the ventilator to maintain a desired patient effort by adjusting a percent support setting. Further, the ventilator can maintain the patient effort to prevent muscle atrophy from non-use while at the same time preventing muscle fatigue from over-loading. Further, determining a desired patient effort range based on a desired treatment metric range in combination with the adjustment of ventilator parameter to maintain a desired treatment metric range can be utilized to improve the treatment of a patient on a ventilator.


As discussed above, method 200A illustrates the method for delivering the first breath during an OPA breath type. Accordingly, method 200A begins after the initiation of ventilation during an OPA breath type.


As illustrated, method 200A includes a retrieving operation 206. During the retrieving operation 206, the ventilator retrieves a desired patient effort range. The desired patient effort range represents a desired parameter from the patient effort profile over each breath. The desired patient effort may be a maximum, mean, root mean square (RMS), minimum or any other appropriate statistic of the a pressure waveform or patient muscle waveform during one breath or a window of multiple breaths. In one embodiment, the desired patient effort range (e.g., a desired peak muscle pressure) is retrieved from input or a selection made by the clinician. In this embodiment, the desired patient effort range does not change unless another range is entered by the clinician. In one embodiment, the desired patient effort ranges is from about 5 cm of H2O to about 10 cm of H2O. In other embodiments, the desired patient effort range is from about 4 cm H2O to about 12 cm of H2O. In some embodiments, the desired patient effort range is from about 6 cm H2O to about 9 cm of H2O. The desired patient effort range may not even be a range at all, but rather be a set value. Accordingly, the desired patient effort range may be 5 cm of H2O, 6 cm of H2O, 7 cm of H2O, 7.5 cm of H2O, 8 cm of H2O, 9 cm of H2O, or 10 cm of H2O, for example. These lists are not meant to be limiting. Any suitable patient effort range to improve the health of the patient may be input by the operator and/or utilized by the ventilator.


In another embodiment in which the ventilator is attempting to improve the treatment of the patient by determining the desired patient effort range based on a desired treatment metric range, the desired patient effort range is retrieved from a determination made by the ventilator during the retrieving operation 206. In this embodiment, the ventilator also retrieves during the retrieving operation 206 one or more one ventilator parameters from a ventilator determination about whether or not the current treatment metric is within the desired treatment range. An embodiment of a method for improving the treatment of the patient by utilizing a desired treatment metric range is illustrated in FIG. 3 and discussed in detail below.


Method 200A also includes an estimating operation 208. During the estimating operation 208 the ventilator estimates an initial percent support setting based on the desired patient effort range. The initial percent support setting as used herein is the percent support setting applied to at least the first breath delivered to the patient during execution of the OPA breath type. The initial percent support setting (k) is held constant over one breath. In one embodiment, the support module estimates the initial percent support setting by utilizing the follow equation based on the equation of motion:

Patient Effort(t)=(1.0−k)[Ep∫Qpdt+QpRp].

The ventilator selects a Patient Effort (t) from the desired patient effort range and utilizes predetermined settings for the remaining parameters that cannot be determined since this is the first delivered breath. The predetermined settings may vary based on other parameters input by the clinician.


Next, method 200A includes a calculating first target airway pressure operation 210. During the calculating first target airway pressure operation 210, the ventilator calculates a first target airway pressure based on the initial percent support setting. The first target airway pressure is calculated for a point in the ventilation circuit that is proximal to the lung and would best assist the patient's inspiratory muscles to the degree as estimated in the initial percent support setting. The target airway pressure is calculated based on the equation of motion, such as by utilizing the following equation:

Target Airway Pressure(t)=k[Ep∫Qpdt+QpRp].


Method 200A also includes a first delivery operation 212. During the first delivery operation 212, the ventilator delivers a target airway pressure to a patient. The target airway pressure is delivered after an inspiratory trigger is detected. A patient trigger is calculated based on the at least one monitored parameter, such as inspiration flow. In some embodiments, sensors, such as flow sensors, may detect changes in patient parameters indicative of patient triggering. The target airway pressure delivered by the ventilator during the first delivery operation 212 is an initial target airway pressure calculated by the ventilator based on the initial percent support setting.


After the delivery of the target airway pressure by the ventilator during first delivery operation 212, the breath cycles to exhalation. As discussed above, method 200B illustrates the method for delivering any breath after the delivery of the first breath during an OPA breath type. Accordingly, method 200B begins during exhalation after any breath delivered during the OPA breath type.


As illustrated, method 200B also includes the retrieving operation 206. During the retrieving operation 206, the ventilator retrieves the current desired patient effort range. In some embodiments, the ventilator during the retrieve operation 206 further retrieves the desired treatment metric range, the current treatment metric, and one or ventilator parameters based on the desired treatment metric range. The desired patient effort range is changed by clinician input and/or a ventilator determination. For example, the clinician may change the desired patient effort range from 5 cm of H2O to 10 cm of H2O to a range of 7 cm of H2O to 9 cm of H2O. In another example, the ventilator determines a patient effort range based on an input desired treatment metric range from an operator. In another embodiment, the clinician enters a new desired treatment metric range, such as a new RSBI setting range, which may be retrieved by the ventilator during the retrieving operation 206. Accordingly, the ventilator during retrieving operation 206 continuously retrieves the currently desired patient effort range and/or desired treatment metric range for the OPA breath type.


Further, method 200B includes a calculating current patient effort operation 214. During the calculating current patient effort operation 214, the ventilator calculates the current patient effort. The current patient effort or actual patient effort as used herein represents a time profile that depicts the amount of effort exerted by the patient during the last delivered breath. The current patient effort is calculated every control cycle based on the equation of motion and estimated patient parameters. The ventilator estimates patient parameters based on the measurements directly or indirectly related to monitored patient parameters. In some embodiments, the estimated patient parameters include lung compliance (inverse of elastance) and/or lung/airway resistance. In further embodiments, the estimated lung compliance, lung elastance and/or lung/airway resistance are estimated based on monitored flow and/or the equation of motion. The estimated patient parameters may be estimated by any processor found in the ventilator.


Next, method 200 further includes a decision operation 216. The decision operation 216 determines if the current patient effort is within the desired patient effort range. The ventilator during decision operation 216 utilizes the most updated desired patient effort as retrieved by the ventilator during the retrieving operation 206. If the ventilator during the decision operation 216 determines that the current patient effort is within the desired patient effort range, then the ventilator selects to perform delivery operation 222. If the ventilator during the decision operation 216 determines that the current patient effort is not within the desired patient effort range, then the ventilator selects to perform calculating adjusted percent support setting operation 218.


Method 200 includes a calculating adjusted percent support setting operation 218. During the calculating adjusted percent support setting operation 218, the ventilator calculates or determines an adjusted percent support setting. In one embodiment, when the current patient effort is greater than the desired patient effort range, the ventilator increases the percent support setting during the calculating adjusted percent support setting operation 218. In an alternative embodiment, when the current patient effort is below the desired patient ranges, the ventilator decreases the percent support setting during the calculating adjusted percent support setting operation 218. In one embodiment, the ventilator adjusts the percent support setting by utilizing an optimization algorithm during the calculating adjusted percent support setting operation 218. Example optimization algorithms are listed below in the Example section.


Next, method 200 includes a calculate an adjusted target airway pressure operation 220. During the calculate operation 220, the ventilator calculates an adjusted target airway pressure based on the received adjusted percent support setting. The adjusted target pressure is calculated every control cycle using the adjusted percent support setting by the ventilator during the calculate an adjusted target airway pressure operation 220. The adjusted support setting (k) is held constant over one breath. The adjusted target airway pressure is calculated for a point in the ventilation circuit that is proximal to the lung and would best assist the patient's inspiratory muscles to the degree as estimated in the initial percent support setting. The adjusted target airway pressure as used herein is the most recently calculated target airway pressure after the calculation of the initial target airway pressure. Accordingly, the adjusted target airway pressure may change periodically based on changes in at least one of the percent support setting, current patient effort, and/or the desired patient effort range. The adjusted support setting (k) is held constant over one breath. The adjusted target pressure is calculated every control cycle based on the equation of motion, such as by utilizing the following equation:

Target Airway Pressure(t)=k[Ep∫Qpdt+QpRp]


Next, method 200 includes an adjusted delivery operation 224. During the delivery operation 224, the ventilator delivers the adjusted target airway pressure to a patient. The ventilator delivers the adjusted target airway pressure to the patient after the detection of a patient initiated inspiratory trigger.


Further, method 200 includes a previous delivery operation 222. During the delivery operation 222, the ventilator delivers the previously delivered target airway pressure to the patient based on the previous percent support setting. The ventilator delivers the previously delivered airway pressure to the patient after the detection of a patient initiated inspiratory trigger. The previously delivered target airway pressure as used herein is the target airway pressure that was delivered during the last preceding breath. Accordingly, in some embodiments, the previously delivered target airway pressure is the initial target airway pressure. The previously delivered target airway pressure is the initial target airway pressure if the initial percent support setting caused the patient to exert a patient effort within the desired patient effort range. In another embodiment, the previously delivered target airway pressure is a previously adjusted target airway pressure. The previously delivered target airway pressure is a previously adjusted target airway pressure if the previously adjusted percent support setting caused the patient to exert a patient effort within the desired patient effort range.


In some embodiments, method 200 includes a display operation. The ventilator during the display operation displays any suitable information for display on a ventilator. In one embodiment, the display operation displays at least one of the current patient effort, the desired patient effort range, the desired treatment metric range, the current treatment metric, the RSBI, the SpO2, the P100, the tidal volume, the VCO2, the respiratory rate, the spontaneous I:E volume, the minute volume, the initial percent support setting, and the adjusted percent support setting.



FIG. 3 illustrates an embodiment of a method 300 for ventilating a patient with a ventilator based on a desired treatment metric range during an OPA breath type. In embodiments, method 300 is performed for every breath or in a predetermined number of breaths.


As illustrated, method 300 includes a receiving operation 301. During the receiving operation 301, the ventilator receives a desired treatment metric range. The desired treatment metric range is received from input or a selection by the clinician. A treatment metric is a ventilator parameter that is indicative of how well a patient treatment is going. In some embodiments, the treatment metric includes RSBI, SpO2, P100, oxygen index, ETCO2, tidal volume, VCO2, respiratory rate, spontaneous I:E ratio, and a minute volume. In some embodiments, the treatment metric range includes a trended or weighted combination of at least one of RSBI, SpO2, P100, oxygen index, ETCO2, tidal volume, VCO2, respiratory rate, spontaneous I:E ratio, and a minute volume. The desired treatment metric range is a range of a ventilator parameter that improves the treatment of the patient. For example, if the treatment metric is RSBI, the desired treatment metric may be a range of an RSBI of less than 105, which helps to decrease the amount of time a ventilator takes to wean a patient from ventilation. In another embodiment, the desired treatment range is represented by a solitary values, such as and RSBI of 100.


Next, method 300 includes a determining operation 302. During the determining operation 302, the ventilator determines the desire patent effort range based on the received desired treatment metric range. The determined desired patient effort range should help the patient achieve a current treatment metric within the desired treatment metric range. The current treatment metric as used herein represents the treatment metric as measured or determined by the ventilator for the patient within the last computational cycle or for the last delivered breath depending upon the treatment metric utilized. In some embodiments, the treatment metric (whether current or desired) is derived from the calculated profiles over numerous breaths. In some embodiments, the treatment metric is the maximum, mean, root mean square (RMS), or any other appropriate statistic of the waveform during one window or a window of multiple breaths.


As illustrated, method 300 includes a monitoring operation 303. During the monitoring operation 303, the ventilator monitors patient parameters. In some embodiments, the patient parameters include the current treatment metric and the current patient effort. The monitoring operation 303 may be performed by sensors and data acquisition subsystems. The sensors may include any suitable sensing device as known by a person of skill in the art for a ventilator. In some embodiments, the sensors are located in the pneumatic system, the breathing circuit, and/or on the patient. In some embodiments, the ventilator during the monitoring operation 303 monitors patient parameters every computational cycle (e.g., 2 milliseconds, 5 milliseconds, 10 milliseconds, etc.) and/or during the delivery of the control pressure. In other embodiments, the trend of the monitored patient parameters are determined and monitored.


Next, method 300 includes a first decision operation 304. The ventilator during first decision operation 304 determines if current patient effort is within the desired patient effort range for at least two consecutive breaths. The ventilator determines if the current patient effort is within the desired patient effort range based on the monitored parameters and/or the received ventilator parameters. If the ventilator during the decision operation 304 determines that the current patient effort is within the desired patient effort range for at least two consecutive breaths, then the ventilator selects to perform second decision operation 305. If the ventilator during the first decision operation 304 determines that the current patient effort is not within the desired patient effort range for at least two consecutive breaths, then the ventilator selects to perform monitoring operation 303.


Next, method 300 includes a second decision operation 305. The ventilator during second decision operation 305 determines if the current treatment metric is outside of the desired treatment metric range. The ventilator determines if the current treatment metric is outside of the desired treatment metric range based on the monitored parameters and/or the received ventilator parameters. If the ventilator during the second decision operation 305 determines that the current treatment metric is not outside of the desired treatment metric range, then the ventilator selects to perform maintaining operation 306. If the ventilator during the decision operation 304 determines that the current treatment metric is outside of the desired treatment metric range, then the ventilator selects to perform adjusting operation 308.


Method 300 includes a maintaining operation 306. During the maintain operation 306, the ventilator maintains the current one or more ventilator parameters. Accordingly, the ventilator utilizes the one or more ventilator parameters as was utilized during the previous breath and/or control cycle. If there was no previous breath and/or control cycle, the ventilator during maintaining operation 306 utilizes predetermined ventilator parameters as set by the ventilator or as set by the operator. In one embodiment, the ventilator parameters include at least one of an oxygen percentage, a rise time, a trigger sensitivity, a peak flow rate, a peak inspiratory pressure, a tidal volume, and a PEEP.


Method 300 also includes an adjusting operation 308. During the adjusting operation 308, the ventilator adjusts the ventilator parameters based on the determination that the current treatment metric is not within the desired treatment metric range. The ventilator adjusts the ventilator parameters by utilizing algorithms and optimization programming techniques to provide advisory input and/or automatic adjustments to ventilation parameters and/or a timed changes in ventilation modality (patient-triggered or ventilator-driven breath delivery) to increase the efficiency and confidence in the predictive nature of the treatment metric. In other words, the ventilator during adjusting operation 308 adjusts the ventilator parameters in an attempt to make the next measured current treatment metric within the desired treatment metric range.


In one embodiment, the treatment algorithm and/or optimization programming incorporates an internal model of the patient respiratory system in interaction with the ventilator to address the relevant interactive dynamics between the patient and the ventilator as well as model and predict changes in patient's respiratory behavior and therapeutic outcome in response to the ongoing treatment protocol delivered by the ventilator. The control system design of the treatment module is envisioned to optimize convergence of the control output or desired patient effort. In some embodiments, the internal model for the treatment algorithm and/or optimization programming incorporates mechanisms for estimating system parameters (respiratory resistance, compliance, and etc.). Additionally, the treatment algorithm and/or the optimization programming may include features to estimate, model, or predict dynamics related to the functioning and interrelationships between inputs (e.g., percent support, SpO2, oxygen mix, and etc.) and output (generated patient effort over time). In further embodiments, the treatment algorithm includes mechanisms to estimate physiologic-based and/or hardware-based dynamics (transients, delays, and etc.). For instance, an example treatment algorithm is listed below in the Example section.


The ventilator retrieves the desired patient effort range and the one or more ventilator parameters as determined by the ventilator during the maintaining operation 306 and the adjusting operation 308 during retrieving operation 206 for utilization in method 200. Accordingly, the ventilator during the retrieving operation 206 may retrieve a determined desired patient effort range and an adjusted one or more ventilator parameters or may retrieve the previously retrieved one or more ventilator parameters for use in method 200.


In some embodiments, a microprocessor-based ventilator that accesses a computer-readable medium having computer-executable instructions for performing the method of ventilating a patient with a medical ventilator is disclosed. This method includes repeatedly performing the steps disclosed in method 200 and/or method 300 above and/or as illustrated in FIGS. 2A, 2B, and/or 3.


In some embodiments, the ventilator system includes: means for retrieving a desired patient effort range; means for estimating an initial percent support setting based on the desired patient effort range; means for calculating a target airway pressure based at least on the initial percent support setting; and means for delivering the target airway pressure to a patient. In some embodiments, the ventilator system further includes: means for calculating current patient effort; means for determining if the current patient effort is above the desired patient effort range; and means for calculating an adjusted percent support setting that is greater than the initial percent support setting. In some embodiments, the ventilator system further includes: means for calculating current patient effort; means for determining if the current patient effort is below the desired patient effort range; and means for repeatedly calculating an adjusted percent support setting that is less than the initial percent support setting.


EXAMPLES

The examples listed below are exemplary only and not meant to be limiting of the disclosure.


Example 1

Example 1 illustrates an embodiment of a pseudo code for the systems and methods of the disclosure. The control objective is to maintain a defined metric of patient's respiratory effort (peak inspiratory muscle pressure (Pmus)) within a desired range by automatic adjustment of the “Percent Support Setting” parameter in an Optimized Proportional Assist Ventilation. The pseudo code illustrated below utilizes an algorithm that incorporates the following aspects:

    • The “Percent Support Setting” parameter is constrained between 0 and 100%.
    • The minimum increment/decrement for “Percent Support Setting”=1.0%
    • The “Percent Support Setting” parameter is adjusted every N breaths.
    • The “Desired Range” (Upper Bound=uBound, Lower Bound=1Bound) is given.
    • The desired bounds are constrained to lie between 0 and a feasible maximum range (with consideration of disease state).
    • The mid-point inside the desired range is the optimum value
    • The average of Peak Pmus over N breaths (AveragePmus) is the metric of choice


      Sample Algorithm:


      The example implementation is envisioned to be done in two stages: (1) bring the measured Peak Pmus within the Desired Range, and (2) optimize measured Peak Pmus to the optimum value.


      The pseudo code embodiment utilizing the algorithm described above is listed below (different sections of the pseudo code are divided by asterisks):














For every breath number i:


// increment breath count, and decide if it is time for adjustment


  MakeAdjustment (i)=false;


  Inc BreathCount;


//Check if it is time for the next adjustment, i.e., the window of N number of breaths have


passed;


 check if the total number of breaths counted is a multiple of the selected window (N).


If (MOD(BreathCount, N)=0)


MakeAdjustment(i)= true;


**************************************************************


// Determine the operating zone.


  If ((AveragePmus)> uBound)


    Direction (i)=1


  Else


    If ((AveragePmus)< lBound)


    Direction(i)=−1


    Else


    Direction(i)=0


Else


  Skip Adjustment


**************************************************************************


***


//Make adjustment algorithm


If (MakeAdjustment(i)= true)


  If (Direction(i)=0); Optimization Stage (Direction=0)


    Run Determine Optimized Percent Support;(algorithm below)


  Else; Bring-In Stage (Direction=1 or −1)


    If (Measured Metric>uBound)


      ControlError=Measured Metric−uBound;


    Else


      ControlError=Measured Metric−lBound;


    If (ABS (ControlError)>(uBound−lBound)) ; ABS( )=absolute value function


      controllerGain(i) =0.5


    Else


      controllerGain(i)=0.2


    If (Direction(i)≠Direction(i−1)); zero-crossing is detected


      controllerGain(i)= controllerGain(i−1)/2.0;


    New PercentSupportSetting=Previous PercentSupportSetting+


controllerGain(i)* ControlError;


**************************************************************************


**


// Determine Optimized Percent Support Setting Algorithm


  OptError=(uBound+lBound)*0.5− Measured Metric;


  Use Gradient Descent optimization method to minimize (ABS(OptError)); Broadly


speaking, increase/decrease PercentSupportSetting by 1 single point (minimum allowable


change) to determine the value that would minimize the magnitude of OptError.









Example 2

Example 2 illustrates an embodiment of a pseudo code for the systems and methods of the disclosure. The control objective is to optimize the treatment outcome based on a defined metric of weighted outcome results. The optimization is achieved by automatic controlling and adjusting ventilator parameters. Patient's respiratory effort (peak inspiratory muscle pressure) is maintained within a desired range by automatic adjustment of the “Percent Support Setting” parameter in Optimized Proportional Assist Ventilation.


The pseudo code illustrated below utilizes an algorithm that incorporates the following aspects:

    • Outcome parameters include: RSBI (Breath Rate/Tidal Volume; weaning index), SpO2 (patient's blood Oxygen saturation), and etCO2 (end tidal CO2).
    • Ventilator settings allowed for automatic adjustment: Percent Support Setting (PAV), O2%, PEEP.
    • The “Percent Support Setting” parameter is constrained between 0 and 100%.
    • O2% is constrained between 21% and 100%.
    • PEEP is constrained between 0 cmH2O and 25 cmH2O.
    • Optimum outcome parameter ranges: RSIB <105 ((breath/minute)/liter), 92%<SpO2<99%, 38 mmHg<etCO2<46 mmHg.
    • The minimum increment/decrement for “Percent Support Setting”=1.0%
    • The “Percent Support Setting” parameter is adjusted every N breaths.
    • The “Desired Range” (Upper Bound=uBound, Lower Bound=1Bound) of patient effort (Pmus) is given.
    • The desired Pmus bounds are constrained to lie between 0 and a feasible maximum range (with consideration of disease state).
    • The average of Peak Pmus over N breaths (AveragePmus) is the metric of choice for achieving the desired range.


      Sample Algorithm:


      The pseudo code embodiment utilizing the algorithm described above is listed below:


      The example implementation is envisioned to be done in two stages:
    • (1) Stage I: Bring the measured Peak Pmus within the Desired Range by adjusting the Percent Support Setting, and;
    • (2) Stage II: While maintaining the Pmus within the desired range (by keeping the Percent Support Setting at the level determined in stage 1 and adjusting it if needed), adjust other ventilator parameters allowed to optimize the treatment outcome or treatment metric.
    • (3) Use the following Cost Function (C) for Stage II optimization:
      • Optimization Goal: {Minimize C};
      • C=α*WeaningMetric+β*OxygenationMetric+Ω*VentilationMetric;
      • A, β, and Ω are relative weighting coefficients (range=0.00−1.00).
      • WeaningMetric=(measured RSBI−105);
      • OxygenationMetric=
        • (93−measured SpO2) if measured SpO2<93
        • 0 if measured SpO2>92
      • VentilationMetric=
        • (40−measured etCO2) if measured etCO2<40 mmHg
        • (measured etCO2−45) if measured etCO2>46 mmHg
        • 0 if 39<measured etCO2<46


          Stage 1 (PAV Percent Support Setting Adjustment): see the Adjustment part of the Example 1 above for algorithms to bring in and maintain peak Pmus within the desired range.


          Stage 2 (Outcome Optimization):
    • Maintain the peak Pmus within the desired range (by keeping the Percent Support Setting at the level determined in stage 1 and adjusting it if needed).
    • Use appropriate Reinforcement Learning and Dynamic Programming algorithms (for example, Gradient Descent) for multiple input parameters to optimize the weighted cost function C by programmed adjustments to PEEP and O2% within their respective allowable ranges.
    • Provide progress reports (statistics, plots, etc.) as appropriate for monitoring purposes.


Those skilled in the art will recognize that the methods and systems of the present disclosure may be implemented in many manners and as such are not to be limited by the foregoing exemplary embodiments and examples. In other words, functional elements being performed by a single or multiple components, in various combinations of hardware and software or firmware, and individual functions, can be distributed among software applications at either the client or server level or both. In this regard, any number of the features of the different embodiments described herein may be combined into single or multiple embodiments, and alternate embodiments having fewer than or more than all of the features herein described are possible. Functionality may also be, in whole or in part, distributed among multiple components, in manners now known or to become known. Thus, myriad software/hardware/firmware combinations are possible in achieving the functions, features, interfaces and preferences described herein. Moreover, the scope of the present disclosure covers conventionally known manners for carrying out the described features and functions and interfaces, and those variations and modifications that may be made to the hardware or software firmware components described herein as would be understood by those skilled in the art now and hereafter.


Numerous other changes may be made which will readily suggest themselves to those skilled in the art and which are encompassed in the spirit of the disclosure and as defined in the appended claims. While various embodiments have been described for purposes of this disclosure, various changes and modifications may be made which are well within the scope of the present invention. Numerous other changes may be made which will readily suggest themselves to those skilled in the art and which are encompassed in the spirit of the disclosure and as defined in the appended claims.

Claims
  • 1. A ventilator system comprising: a pressure generating system, wherein the pressure generating system generates a flow of breathing gas;a ventilation tubing system including a patient interface for connecting the pressure generating system to a patient;one or more sensors operatively coupled to at least one of the pressure generating system, the patient, and the ventilation tubing system, wherein the one or more sensors generate output indicative of an inspiration flow;a support module that receives an initial percent support setting and a desired patient effort range, wherein the support module calculates at least one adjusted percent support setting based at least on determining that a current patient effort falls outside of the desired patient effort range, wherein the at least one adjusted percent support setting is calculated to cause the current patient effort to fall within the desired patient effort range when utilized to calculate an adjusted target airway pressure for delivery to the patient; andan optimized proportional assist (OPA) module, the OPA module calculates an initial target airway pressure based at least on the initial percent support setting, calculates at least one adjusted target airway pressure based at least on the at least one adjusted percent support setting, and utilizes the output indicative of the inspiration flow to determine a patient trigger for delivery of a breath to the patient,wherein the pressure generating system delivers the initial target airway pressure to the patient in response to receiving the initial target airway pressure and delivers the adjusted target airway pressure to the patient in response to receiving the adjusted target airway pressure affecting patient effort.
  • 2. The ventilator system of claim 1, further comprising: a treatment module, the treatment module determines the desired patient effort range based on a desired treatment metric range received from operator input and adjusts at least one ventilator parameter upon determining that a current treatment metric is not within the desired treatment metric range while the current patient effort is within the desired patient effort range for at least two consecutive breaths.
  • 3. The ventilator system of claim 2, wherein the at least one ventilator parameter is at least one of oxygen percentage, rise time, trigger sensitivity, peak flow rate, peak inspiratory pressure, tidal volume, and PEEP.
  • 4. The ventilator system of claim 2, further comprising a display that displays at least one of the current patient effort, the desired patient effort range, the desired treatment metric range, a current treatment metric range, a RSBI, a SpO2, a P100, a tidal volume, a VCO2, a respiratory rate, a spontaneous I:E volume, a minute volume, the initial percent support setting, and the adjust percent support setting.
  • 5. A ventilator system, comprising: means for retrieving a desired patient effort range;means for estimating an initial percent support setting based on the desired patient effort range;means for calculating a current patient effort;means for determining that the current patient effort is outside of the desired patient effort range;means for calculating an adjusted percent support setting based on determining that the current patient effort is outside of the desired patient effort range, wherein the adjusted percent support setting is calculated to cause the current patient effort to fall within the desired patient effort range when utilized to calculate an adjusted target airway pressure for delivery to a patient;means for calculating a target airway pressure based at least on the adjusted percent support setting; andmeans for delivering the target airway pressure to the patient to affect patient effort.
  • 6. The ventilator system of claim 5, further comprising: means for determining that the current patient effort is within the desired patient effort range; andmeans for delivering a previously delivered target airway pressure to the patient based on the means for determining that the current patient effort is within the desired patient effort range, wherein the means for delivering the target airway pressure to the patient is the same as the means for delivering the previously delivered target airway pressure.
  • 7. The ventilator system of claim 5, further comprising: means for receiving a desired treatment metric range from an operator;means for determining that a current treatment metric is not within the desired treatment metric range; andmeans for adjusting at least one ventilator parameter until the current treatment metric is within the desired treatment metric range,wherein a means for determining the desired patient effort range determines the desired patient effort range based on the desired treatment metric range.
  • 8. The ventilator system of claim 7, wherein the at least one ventilator parameter is at least one of oxygen percentage, rise time, trigger sensitivity, peak flow rate, peak inspiratory pressure, tidal volume, and PEEP.
  • 9. The ventilator system of claim 7, wherein the desired treatment metric range is at least one of a trend and a weighted combination of at least one of RSBI, SpO2, P100, Oxygen index, ETCO2, tidal volume, VCO2, respiratory rate, spontaneous I:E ratio, and a minute volume.
  • 10. The ventilator system of claim 7, wherein the desired treatment metric range is a range of at least one of RSBI, SpO2, P100, Oxygen index, ETCO2, tidal volume, VCO2, respiratory rate, spontaneous I:E ratio, and a minute volume.
  • 11. The ventilator system of claim 5, further comprising: means for receiving a desired treatment metric range from an operator,wherein a means for determining the desired patient effort range determines the desired patient effort range based on the desired treatment metric range.
  • 12. The ventilator system of claim 5, wherein the target airway pressure is calculated utilizing a following equation: Target Pressure(t)=k[Ep∫Qpdt+QpRp]wherein Target Pressure (t) is an amount of pressure provided by the ventilator at time t,wherein k is a percent support setting,wherein Ep is a respiratory elastance of the patient,wherein Qp is an instantaneous flow inhaled by the patient, andwherein Rp is a respiratory resistance of the patient.
  • 13. The ventilator system of claim 5, wherein the desired patient effort range is received from at least one of an operator via operator selection from a group of desired patient effort ranges, the operator via an input of a desired patient effort parameter, the ventilator system calculated based on at least one of an at least one monitored patient parameter and ventilator parameters, and the ventilator system via a selection from a group of predetermined patient efforts ranges based on at least one of the at least one monitored patient parameter and the ventilator parameters.
  • 14. The ventilator system of claim 5, wherein the desired patient effort range is from about 5 cm of H2O to about 10 cm of H2O.
US Referenced Citations (885)
Number Name Date Kind
1202125 Tullar Oct 1916 A
1202126 Tullar Oct 1916 A
1241056 Tullar Sep 1917 A
2914067 Meidenbauer Nov 1959 A
3339545 Barnett Sep 1967 A
3584618 Reinhard et al. Jun 1971 A
3628531 Harris Dec 1971 A
3643652 Beltran Feb 1972 A
3722510 Parker Mar 1973 A
3739776 Bird et al. Jun 1973 A
3759249 Fletcher et al. Sep 1973 A
3805780 Cramer et al. Apr 1974 A
3911899 Hattes Oct 1975 A
3941124 Rodewald et al. Mar 1976 A
3952739 Cibulka Apr 1976 A
3957044 Fletcher et al. May 1976 A
3968794 O'Neill Jul 1976 A
3968795 O'Neill et al. Jul 1976 A
3985131 Buck et al. Oct 1976 A
3991304 Hillsman Nov 1976 A
4056098 Michel et al. Nov 1977 A
4112931 Burns Sep 1978 A
4127123 Bird Nov 1978 A
4150670 Jewett et al. Apr 1979 A
4258718 Goldman Mar 1981 A
4281651 Cox Aug 1981 A
4284075 Krasberg Aug 1981 A
4294242 Cowans Oct 1981 A
4299236 Poirier Nov 1981 A
4305388 Brisson Dec 1981 A
4316182 Hodgson Feb 1982 A
4340044 Levy et al. Jul 1982 A
4366821 Wittmaier et al. Jan 1983 A
4433693 Hochstein Feb 1984 A
4440166 Winkler et al. Apr 1984 A
4442835 Carnegie Apr 1984 A
4448192 Stawitcke et al. May 1984 A
4459982 Fry Jul 1984 A
4498471 Kranz et al. Feb 1985 A
4503850 Pasternak Mar 1985 A
4506667 Ansite Mar 1985 A
4522639 Ansite et al. Jun 1985 A
4527557 DeVries et al. Jul 1985 A
4550726 McEwen Nov 1985 A
4606340 Ansite Aug 1986 A
4630605 Pasternack Dec 1986 A
4637385 Rusz Jan 1987 A
4648407 Sackner Mar 1987 A
4653493 Hoppough Mar 1987 A
4655213 Rapoport et al. Apr 1987 A
4752089 Carter Jun 1988 A
4773411 Downs Sep 1988 A
4805612 Jensen Feb 1989 A
4805613 Bird Feb 1989 A
4821709 Jensen Apr 1989 A
4870960 Hradek Oct 1989 A
4921642 LaTorraca May 1990 A
4939647 Clough et al. Jul 1990 A
4954799 Kumar Sep 1990 A
4971052 Edwards Nov 1990 A
4984158 Hillsman Jan 1991 A
4986268 Tehrani Jan 1991 A
4990894 Loescher et al. Feb 1991 A
5022393 McGrady et al. Jun 1991 A
5044362 Younes Sep 1991 A
5048515 Sanso Sep 1991 A
5057822 Hoffman Oct 1991 A
5072737 Goulding Dec 1991 A
5094235 Westenskow et al. Mar 1992 A
5107830 Younes Apr 1992 A
5107831 Halpern et al. Apr 1992 A
5148802 Sanders et al. Sep 1992 A
5150291 Cummings et al. Sep 1992 A
5156145 Flood et al. Oct 1992 A
5161525 Kimm et al. Nov 1992 A
5165397 Arp Nov 1992 A
5165398 Bird Nov 1992 A
5237987 Anderson et al. Aug 1993 A
5239995 Estes et al. Aug 1993 A
5271389 Isaza et al. Dec 1993 A
5273031 Olsson et al. Dec 1993 A
5279549 Ranford Jan 1994 A
5299568 Forare et al. Apr 1994 A
5301921 Kumar Apr 1994 A
5307795 Whitwam et al. May 1994 A
5313937 Zdrojkowski May 1994 A
5315989 Tobia May 1994 A
5316009 Yamada May 1994 A
5319540 Isaza et al. Jun 1994 A
5322059 Walther Jun 1994 A
5325861 Goulding Jul 1994 A
5333606 Schneider et al. Aug 1994 A
5339807 Carter Aug 1994 A
5343857 Schneider et al. Sep 1994 A
5351522 Lura Oct 1994 A
5353788 Miles Oct 1994 A
5357946 Kee et al. Oct 1994 A
5365922 Raemer Nov 1994 A
5368019 LaTorraca Nov 1994 A
5383449 Forare et al. Jan 1995 A
5385142 Brady et al. Jan 1995 A
5388575 Taube Feb 1995 A
5390666 Kimm et al. Feb 1995 A
5398676 Press et al. Mar 1995 A
5398682 Lynn Mar 1995 A
5401135 Stoen et al. Mar 1995 A
5402796 Packer et al. Apr 1995 A
5407174 Kumar Apr 1995 A
5413110 Cummings et al. May 1995 A
5429123 Shaffer et al. Jul 1995 A
5433193 Sanders et al. Jul 1995 A
5438980 Phillips Aug 1995 A
5443075 Holscher Aug 1995 A
5452714 Anderson et al. Sep 1995 A
5477860 Essen Moller Dec 1995 A
5485833 Dietz Jan 1996 A
5492113 Estes et al. Feb 1996 A
5503147 Bertheau Apr 1996 A
5507282 Younes Apr 1996 A
5513631 McWilliams May 1996 A
5517983 Deighan et al. May 1996 A
5520071 Jones May 1996 A
5524615 Power Jun 1996 A
5524616 Smith et al. Jun 1996 A
RE35295 Estes et al. Jul 1996 E
5531221 Power Jul 1996 A
5535738 Estes et al. Jul 1996 A
5540218 Jones et al. Jul 1996 A
5540220 Gropper et al. Jul 1996 A
5540222 Younes Jul 1996 A
5542415 Brady Aug 1996 A
5544674 Kelly Aug 1996 A
5549106 Gruenke et al. Aug 1996 A
5551418 Estes et al. Sep 1996 A
5551419 Froehlich et al. Sep 1996 A
5572993 Kurome et al. Nov 1996 A
5582163 Bonassa Dec 1996 A
5582182 Hillsman Dec 1996 A
5596984 O'Mahoney et al. Jan 1997 A
5598838 Servidio et al. Feb 1997 A
5605151 Lynn Feb 1997 A
5608647 Rubsamen et al. Mar 1997 A
5623923 Bertheau et al. Apr 1997 A
5630411 Holscher May 1997 A
5632269 Zdrojkowski May 1997 A
5632270 O'Mahoney et al. May 1997 A
5645048 Brodsky et al. Jul 1997 A
5660171 Kimm et al. Aug 1997 A
5662099 Tobia et al. Sep 1997 A
5664560 Merrick et al. Sep 1997 A
5664562 Bourdon Sep 1997 A
5671767 Kelly Sep 1997 A
5672041 Ringdahl et al. Sep 1997 A
5673689 Power Oct 1997 A
5685318 Elghazzawi Nov 1997 A
5692497 Schnitzer et al. Dec 1997 A
5694923 Hete et al. Dec 1997 A
5704345 Berthon-Jones Jan 1998 A
5715812 Deighan et al. Feb 1998 A
5720278 Lachmann Feb 1998 A
5730121 Hawkins, Jr. et al. Mar 1998 A
5735267 Tobia Apr 1998 A
5743253 Castor et al. Apr 1998 A
5752506 Richardson May 1998 A
5752509 Lachmann et al. May 1998 A
5762480 Adahan Jun 1998 A
5765558 Psaros et al. Jun 1998 A
5771884 Yarnall et al. Jun 1998 A
5782233 Niemi et al. Jul 1998 A
5791339 Winter Aug 1998 A
5794615 Estes Aug 1998 A
5794986 Gansel et al. Aug 1998 A
5803065 Zdrojkowski et al. Sep 1998 A
5810741 Essen Moller Sep 1998 A
5813399 Isaza et al. Sep 1998 A
5823187 Estes et al. Oct 1998 A
5826575 Lall Oct 1998 A
5829441 Kidd et al. Nov 1998 A
5832916 Lundberg Nov 1998 A
5832919 Kano et al. Nov 1998 A
5860418 Lundberg Jan 1999 A
5864938 Gansel et al. Feb 1999 A
5865168 Isaza Feb 1999 A
5868133 DeVries et al. Feb 1999 A
5876353 Riff Mar 1999 A
5878744 Pfeiffer Mar 1999 A
5881717 Isaza Mar 1999 A
5881723 Wallace et al. Mar 1999 A
5884622 Younes Mar 1999 A
5884623 Winter Mar 1999 A
5891023 Lynn Apr 1999 A
5901704 Estes et al. May 1999 A
5904141 Estes et al. May 1999 A
5909731 O'Mahony et al. Jun 1999 A
5915379 Wallace et al. Jun 1999 A
5915380 Wallace et al. Jun 1999 A
5915382 Power Jun 1999 A
5918597 Jones et al. Jul 1999 A
5921238 Bourdon Jul 1999 A
5927274 Servidio et al. Jul 1999 A
5931160 Gilmore et al. Aug 1999 A
5934274 Merrick et al. Aug 1999 A
5937853 Strom Aug 1999 A
5957130 Krahbichler et al. Sep 1999 A
5964218 Smith et al. Oct 1999 A
5970975 Estes et al. Oct 1999 A
5975081 Hood et al. Nov 1999 A
5996580 Swann Dec 1999 A
6024089 Wallace et al. Feb 2000 A
6029660 Calluaud et al. Feb 2000 A
6029664 Zdrojkowski et al. Feb 2000 A
6029665 Berthon-Jones Feb 2000 A
6041777 Faithfull et al. Mar 2000 A
6041780 Richard et al. Mar 2000 A
6047860 Sanders Apr 2000 A
6076523 Jones et al. Jun 2000 A
6105575 Estes et al. Aug 2000 A
6109259 Fitzgerald Aug 2000 A
6112744 Hognelid Sep 2000 A
6116240 Merrick et al. Sep 2000 A
6116464 Sanders Sep 2000 A
6123073 Schlawin et al. Sep 2000 A
6123074 Hete et al. Sep 2000 A
6135105 Lampotang et al. Oct 2000 A
6135106 Dirks et al. Oct 2000 A
6139506 Heinonen Oct 2000 A
6142150 O'Mahony et al. Nov 2000 A
6148814 Clemmer et al. Nov 2000 A
6158432 Biondi et al. Dec 2000 A
6161539 Winter Dec 2000 A
6168568 Gavriely Jan 2001 B1
6196222 Heinonen et al. Mar 2001 B1
6209540 Sugiura et al. Apr 2001 B1
6213119 Brydon et al. Apr 2001 B1
6213120 Block et al. Apr 2001 B1
6216690 Keitel et al. Apr 2001 B1
6220245 Takabayashi et al. Apr 2001 B1
6223064 Lynn et al. Apr 2001 B1
6227197 Fitzgerald May 2001 B1
6240919 MacDonald et al. Jun 2001 B1
6253765 Hognelid et al. Jul 2001 B1
6257234 Sun Jul 2001 B1
6258039 Okamoto et al. Jul 2001 B1
6269812 Wallace et al. Aug 2001 B1
6273088 Hillsman Aug 2001 B1
6273444 Power Aug 2001 B1
6283119 Bourdon Sep 2001 B1
6302105 Wickham et al. Oct 2001 B1
6302851 Gedeon Oct 2001 B1
6305372 Servidio Oct 2001 B1
6305373 Wallace et al. Oct 2001 B1
6305374 Zdrojkowski et al. Oct 2001 B1
6321748 O'Mahoney Nov 2001 B1
6325785 Babkes et al. Dec 2001 B1
6341604 Kellon Jan 2002 B1
6342039 Lynn et al. Jan 2002 B1
6345619 Finn Feb 2002 B1
6357438 Hansen Mar 2002 B1
6360745 Wallace et al. Mar 2002 B1
6369838 Wallace et al. Apr 2002 B1
6371113 Tobia et al. Apr 2002 B1
6371114 Schmidt et al. Apr 2002 B1
6390091 Banner May 2002 B1
6397838 Zimlich, Jr. et al. Jun 2002 B1
6412483 Jones et al. Jul 2002 B1
6427689 Estes et al. Aug 2002 B1
6431169 do Val et al. Aug 2002 B1
6439229 Du et al. Aug 2002 B1
6446630 Todd, Jr. Sep 2002 B1
6457472 Schwartz et al. Oct 2002 B1
6467477 Frank et al. Oct 2002 B1
6467478 Merrick et al. Oct 2002 B1
6467481 Eswarappa Oct 2002 B1
6484719 Berthon-Jones Nov 2002 B1
6512938 Claure et al. Jan 2003 B2
6526970 DeVries et al. Mar 2003 B2
6532956 Hill Mar 2003 B2
6532957 Berthon-Jones Mar 2003 B2
6532958 Buan et al. Mar 2003 B1
6532959 Berthon-Jones Mar 2003 B1
6532960 Yurko Mar 2003 B1
6536429 Pavlov et al. Mar 2003 B1
6536433 Cewers Mar 2003 B1
6539940 Zdrojkowski et al. Apr 2003 B2
6543449 Woodring et al. Apr 2003 B1
6546930 Emerson et al. Apr 2003 B1
6553991 Isaza Apr 2003 B1
6553992 Berthon-Jones et al. Apr 2003 B1
6557553 Borrello May 2003 B1
6557554 Sugiura May 2003 B1
6561187 Schmidt et al. May 2003 B2
6571795 Bourdon Jun 2003 B2
6575163 Berthon-Jones Jun 2003 B1
6577884 Boas Jun 2003 B1
6578575 Jonson Jun 2003 B1
6581597 Sugiura Jun 2003 B2
6588422 Berthon-Jones et al. Jul 2003 B1
6595213 Bennarsten Jul 2003 B2
6607481 Clawson Aug 2003 B1
6609016 Lynn Aug 2003 B1
6609517 Estes et al. Aug 2003 B1
6612995 Leonhardt et al. Sep 2003 B2
6622726 Du Sep 2003 B1
6626175 Jafari et al. Sep 2003 B2
6629527 Estes et al. Oct 2003 B1
6629934 Mault et al. Oct 2003 B2
6631716 Robinson et al. Oct 2003 B1
6640806 Yurko Nov 2003 B2
6644310 Delache et al. Nov 2003 B1
6644312 Berthon-Jones et al. Nov 2003 B2
6651657 Manigel et al. Nov 2003 B1
6655383 Lundberg Dec 2003 B1
6668824 Isaza et al. Dec 2003 B1
6671529 Claure et al. Dec 2003 B2
6672300 Grant Jan 2004 B1
6675797 Berthon-Jones Jan 2004 B1
6675801 Wallace et al. Jan 2004 B2
6679258 Strom Jan 2004 B1
6688307 Berthon-Jones Feb 2004 B2
6708691 Hayek Mar 2004 B1
6718974 Moberg Apr 2004 B1
6723055 Hoffman Apr 2004 B2
6725447 Gilman et al. Apr 2004 B1
6739337 Isaza May 2004 B2
6748252 Lynn et al. Jun 2004 B2
6752151 Hill Jun 2004 B2
6755193 Berthon-Jones et al. Jun 2004 B2
6758216 Berthon-Jones Jul 2004 B1
6758217 Younes Jul 2004 B1
6760608 Lynn Jul 2004 B2
6761165 Strickland, Jr. Jul 2004 B2
6761167 Nadjafizadeh et al. Jul 2004 B1
6761168 Nadjafizadeh et al. Jul 2004 B1
6796305 Banner et al. Sep 2004 B1
6810876 Berthon-Jones Nov 2004 B2
6814074 Nadjafizadeh et al. Nov 2004 B1
6820613 Wankebach et al. Nov 2004 B2
6820618 Banner et al. Nov 2004 B2
6823866 Jafari et al. Nov 2004 B2
6837241 Samzelius Jan 2005 B2
6837242 Younes Jan 2005 B2
6837244 Yagi et al. Jan 2005 B2
6854462 Berthon-Jones et al. Feb 2005 B2
6860858 Green et al. Mar 2005 B2
6866040 Bourdon Mar 2005 B1
6868346 Larson et al. Mar 2005 B2
6877511 DeVries et al. Apr 2005 B2
6899101 Haston et al. May 2005 B2
6899103 Hood et al. May 2005 B1
6910480 Berthon-Jones Jun 2005 B1
6915803 Berthon-Jones et al. Jul 2005 B2
6920878 Sinderby et al. Jul 2005 B2
6932084 Estes et al. Aug 2005 B2
6948497 Zdrojkowski et al. Sep 2005 B2
6949133 McCombs et al. Sep 2005 B2
6960854 Nadjafizadeh et al. Nov 2005 B2
6976487 Melker et al. Dec 2005 B1
6990977 Calluaud et al. Jan 2006 B1
6997881 Green et al. Feb 2006 B2
7000610 Bennarsten et al. Feb 2006 B2
7000612 Jafari et al. Feb 2006 B2
7008380 Rees et al. Mar 2006 B1
7013892 Estes et al. Mar 2006 B2
7021310 Sinderby et al. Apr 2006 B1
7032589 Kerechanin, II et al. Apr 2006 B2
7036504 Wallace et al. May 2006 B2
7040320 Fjeld et al. May 2006 B2
7040321 Göbel May 2006 B2
7055522 Berthon-Jones Jun 2006 B2
7066173 Banner et al. Jun 2006 B2
7077131 Hansen Jul 2006 B2
7081095 Lynn et al. Jul 2006 B2
RE39225 Isaza et al. Aug 2006 E
7089930 Adams et al. Aug 2006 B2
7089936 Madaus et al. Aug 2006 B2
7089937 Berthon-Jones et al. Aug 2006 B2
7092757 Larson et al. Aug 2006 B2
7096866 Be'eri et al. Aug 2006 B2
7100607 Zdrojkowski et al. Sep 2006 B2
7100609 Berthon-Jones et al. Sep 2006 B2
7117438 Wallace et al. Oct 2006 B2
7137389 Berthon-Jones Nov 2006 B2
7152598 Morris et al. Dec 2006 B2
7162296 Leonhardt et al. Jan 2007 B2
7210478 Banner et al. May 2007 B2
7225013 Geva et al. May 2007 B2
7229430 Hickle et al. Jun 2007 B2
7246618 Habashi Jul 2007 B2
7255103 Bassin Aug 2007 B2
7267121 Ivri Sep 2007 B2
7267122 Hill Sep 2007 B2
7270126 Wallace et al. Sep 2007 B2
7270128 Berthon-Jones et al. Sep 2007 B2
7275540 Bolam et al. Oct 2007 B2
7296573 Estes et al. Nov 2007 B2
7297119 Westbrook et al. Nov 2007 B2
7305987 Schöller et al. Dec 2007 B2
7320320 Berthon-Jones Jan 2008 B2
7331343 Schmidt et al. Feb 2008 B2
7334578 Biondi et al. Feb 2008 B2
7347204 Lindsey et al. Mar 2008 B1
7353824 Forsyth et al. Apr 2008 B1
7367337 Berthon-Jones et al. May 2008 B2
7369757 Farbarik May 2008 B2
7370650 Nadjafizadeh et al. May 2008 B2
RE40402 Leonhardt et al. Jun 2008 E
7398115 Lynn Jul 2008 B2
7406870 Seto Aug 2008 B2
7428902 Du et al. Sep 2008 B2
7448381 Sasaki et al. Nov 2008 B2
7455583 Taya Nov 2008 B2
7455717 Sprinkle Nov 2008 B2
7460959 Jafari Dec 2008 B2
7472702 Beck et al. Jan 2009 B2
7475685 Dietz et al. Jan 2009 B2
7484508 Younes Feb 2009 B2
7487773 Li Feb 2009 B2
7495546 Lintell et al. Feb 2009 B2
7509957 Duquette et al. Mar 2009 B2
7516742 Stenzler et al. Apr 2009 B2
7520279 Berthon-Jones Apr 2009 B2
7527054 Misholi May 2009 B2
7533670 Freitag et al. May 2009 B1
7556038 Kirby et al. Jul 2009 B2
7588031 Truschel et al. Sep 2009 B2
7591830 Rutter Sep 2009 B2
7610914 Bolam et al. Nov 2009 B2
7617824 Doyle Nov 2009 B2
7621270 Morris et al. Nov 2009 B2
7621271 Brugnoli Nov 2009 B2
7644713 Berthon-Jones Jan 2010 B2
7654802 Crawford, Jr. et al. Feb 2010 B2
7668579 Lynn Feb 2010 B2
7672720 Heath Mar 2010 B2
7678058 Patangay et al. Mar 2010 B2
7678061 Lee et al. Mar 2010 B2
7682312 Lurie Mar 2010 B2
7690378 Turcott Apr 2010 B1
7694677 Tang Apr 2010 B2
7697990 Ujhazy et al. Apr 2010 B2
7708016 Zaiser et al. May 2010 B2
7717110 Kane et al. May 2010 B2
7717111 Schneider et al. May 2010 B2
7717113 Andrieux May 2010 B2
7722546 Madaus et al. May 2010 B2
D618356 Ross Jun 2010 S
7727160 Green et al. Jun 2010 B2
7730886 Berthon-Jones Jun 2010 B2
7751894 Freeberg Jul 2010 B1
7758503 Lynn et al. Jul 2010 B2
7763097 Federspiel et al. Jul 2010 B2
7770578 Estes et al. Aug 2010 B2
7779834 Calluaud et al. Aug 2010 B2
7784461 Figueiredo et al. Aug 2010 B2
7793659 Breen Sep 2010 B2
7802571 Tehrani Sep 2010 B2
7810496 Estes et al. Oct 2010 B2
7810497 Pittman et al. Oct 2010 B2
7819815 Younes Oct 2010 B2
7823588 Hansen Nov 2010 B2
7849854 DeVries et al. Dec 2010 B2
7855716 McCreary et al. Dec 2010 B2
7866318 Bassin Jan 2011 B2
7874293 Gunaratnam et al. Jan 2011 B2
D632796 Ross et al. Feb 2011 S
D632797 Ross et al. Feb 2011 S
7891354 Farbarik Feb 2011 B2
7893560 Carter Feb 2011 B2
7914459 Green et al. Mar 2011 B2
D638852 Skidmore et al. May 2011 S
7934499 Berthon-Jones May 2011 B2
7984714 Hausmann et al. Jul 2011 B2
D643535 Ross et al. Aug 2011 S
7992557 Nadjafizadeh et al. Aug 2011 B2
8001967 Wallace et al. Aug 2011 B2
8002711 Wood et al. Aug 2011 B2
D645158 Sanchez et al. Sep 2011 S
8021310 Sanborn et al. Sep 2011 B2
D649157 Skidmore et al. Nov 2011 S
D652521 Ross et al. Jan 2012 S
D652936 Ross et al. Jan 2012 S
D653749 Winter et al. Feb 2012 S
8113062 Graboi et al. Feb 2012 B2
D655405 Winter et al. Mar 2012 S
D655809 Winter et al. Mar 2012 S
D656237 Sanchez et al. Mar 2012 S
8181648 Perine et al. May 2012 B2
8210173 Vandine Jul 2012 B2
8210174 Farbarik Jul 2012 B2
8240684 Ross et al. Aug 2012 B2
8267085 Jafari et al. Sep 2012 B2
8272379 Jafari et al. Sep 2012 B2
8272380 Jafari et al. Sep 2012 B2
8302600 Andrieux et al. Nov 2012 B2
8302602 Andrieux et al. Nov 2012 B2
8457706 Baker, Jr. Jun 2013 B2
D692556 Winter Oct 2013 S
D693001 Winter Nov 2013 S
D701601 Winter Mar 2014 S
8792949 Baker, Jr. Jul 2014 B2
20010004893 Biondi Jun 2001 A1
20010035186 Hill Nov 2001 A1
20020153006 Zimlich et al. Oct 2002 A1
20020153009 Chornyj et al. Oct 2002 A1
20020185126 Krebs Dec 2002 A1
20030010339 Banner Jan 2003 A1
20030121519 Estes Jul 2003 A1
20030176804 Melker Sep 2003 A1
20040003814 Banner et al. Jan 2004 A1
20040050387 Younes Mar 2004 A1
20040149282 Hickle Aug 2004 A1
20050039748 Andrieux Feb 2005 A1
20050121035 Martin Jun 2005 A1
20050139212 Bourdon Jun 2005 A1
20050172965 Thulin Aug 2005 A1
20060009708 Rapoport et al. Jan 2006 A1
20060060198 Aylsworth et al. Mar 2006 A1
20060112959 Mechlenburg et al. Jun 2006 A1
20060142815 Tehrani et al. Jun 2006 A1
20060144397 Wallace et al. Jul 2006 A1
20060155206 Lynn Jul 2006 A1
20060155207 Lynn et al. Jul 2006 A1
20060155336 Heath Jul 2006 A1
20060161071 Lynn et al. Jul 2006 A1
20060174884 Habashi Aug 2006 A1
20060178591 Hempfling Aug 2006 A1
20060189880 Lynn et al. Aug 2006 A1
20060195041 Lynn et al. Aug 2006 A1
20060235324 Lynn Oct 2006 A1
20060241708 Boute Oct 2006 A1
20060243275 Ruckdeschel et al. Nov 2006 A1
20060249148 Younes Nov 2006 A1
20060264762 Starr Nov 2006 A1
20060272642 Chalvignac Dec 2006 A1
20060278223 Younes Dec 2006 A1
20070000494 Banner Jan 2007 A1
20070017510 Riedo Jan 2007 A1
20070017515 Wallace et al. Jan 2007 A1
20070027375 Melker et al. Feb 2007 A1
20070028921 Banner et al. Feb 2007 A1
20070044796 Zdrojkowski et al. Mar 2007 A1
20070044799 Hete et al. Mar 2007 A1
20070044805 Wedler et al. Mar 2007 A1
20070066961 Rutter Mar 2007 A1
20070072541 Daniels, II et al. Mar 2007 A1
20070077200 Baker Apr 2007 A1
20070093721 Lynn et al. Apr 2007 A1
20070129647 Lynn Jun 2007 A1
20070149860 Lynn et al. Jun 2007 A1
20070151563 Ozaki Jul 2007 A1
20070157931 Parker et al. Jul 2007 A1
20070163579 Li et al. Jul 2007 A1
20070167853 Melker et al. Jul 2007 A1
20070191697 Lynn et al. Aug 2007 A1
20070203448 Melker et al. Aug 2007 A1
20070215146 Douglas et al. Sep 2007 A1
20070215154 Borrello Sep 2007 A1
20070227537 Bemister et al. Oct 2007 A1
20070232951 Euliano et al. Oct 2007 A1
20070272241 Sanborn et al. Nov 2007 A1
20070272242 Sanborn et al. Nov 2007 A1
20070277823 Al-Ali et al. Dec 2007 A1
20070284361 Nadjafizadeh et al. Dec 2007 A1
20080000479 Elaz et al. Jan 2008 A1
20080011301 Qian Jan 2008 A1
20080017189 Ruckdeschel et al. Jan 2008 A1
20080017198 Ivri Jan 2008 A1
20080029097 Schatzl Feb 2008 A1
20080035145 Adams et al. Feb 2008 A1
20080045813 Phuah et al. Feb 2008 A1
20080053441 Gottlib et al. Mar 2008 A1
20080053443 Estes et al. Mar 2008 A1
20080053444 Estes et al. Mar 2008 A1
20080066752 Baker et al. Mar 2008 A1
20080066753 Martin et al. Mar 2008 A1
20080072896 Setzer et al. Mar 2008 A1
20080072901 Habashi Mar 2008 A1
20080072902 Setzer et al. Mar 2008 A1
20080077033 Figueiredo et al. Mar 2008 A1
20080078390 Milne et al. Apr 2008 A1
20080081974 Pav Apr 2008 A1
20080083644 Janbakhsh et al. Apr 2008 A1
20080092894 Nicolazzi et al. Apr 2008 A1
20080097234 Nicolazzi et al. Apr 2008 A1
20080110461 Mulqueeny et al. May 2008 A1
20080110462 Chekal et al. May 2008 A1
20080142012 Farnsworth et al. Jun 2008 A1
20080163872 Negele et al. Jul 2008 A1
20080178880 Christopher et al. Jul 2008 A1
20080178882 Christopher et al. Jul 2008 A1
20080183095 Austin et al. Jul 2008 A1
20080185002 Berthon-Jones et al. Aug 2008 A1
20080196720 Kollmeyer et al. Aug 2008 A1
20080200775 Lynn Aug 2008 A1
20080200819 Lynn et al. Aug 2008 A1
20080202528 Carter et al. Aug 2008 A1
20080216832 Carter et al. Sep 2008 A1
20080216833 Pujol et al. Sep 2008 A1
20080230065 Heinonen Sep 2008 A1
20080234595 Ranieri et al. Sep 2008 A1
20080236582 Tehrani Oct 2008 A1
20080251079 Richey Oct 2008 A1
20080257349 Hedner et al. Oct 2008 A1
20080276939 Tiedje Nov 2008 A1
20080283061 Tiedje Nov 2008 A1
20080295839 Habashi Dec 2008 A1
20080308105 Alder et al. Dec 2008 A1
20080314385 Brunner et al. Dec 2008 A1
20090020120 Schatzl et al. Jan 2009 A1
20090038616 Mulcahy et al. Feb 2009 A1
20090056719 Newman, Jr. Mar 2009 A1
20090078258 Bowman et al. Mar 2009 A1
20090084381 DeVries et al. Apr 2009 A1
20090095298 Gunaratnam et al. Apr 2009 A1
20090107502 Younes Apr 2009 A1
20090114224 Handzsuj et al. May 2009 A1
20090139522 Thomson et al. Jun 2009 A1
20090159082 Eger Jun 2009 A1
20090165795 Nadjafizadeh et al. Jul 2009 A1
20090171176 Andersohn Jul 2009 A1
20090171226 Campbell et al. Jul 2009 A1
20090173347 Berthon-Jones Jul 2009 A1
20090188502 Tiedje Jul 2009 A1
20090199855 Davenport Aug 2009 A1
20090205661 Stephenson et al. Aug 2009 A1
20090205663 Vandine et al. Aug 2009 A1
20090221926 Younes Sep 2009 A1
20090229611 Martin et al. Sep 2009 A1
20090241951 Jafari et al. Oct 2009 A1
20090241952 Nicolazzi et al. Oct 2009 A1
20090241953 Vandine et al. Oct 2009 A1
20090241955 Jafari et al. Oct 2009 A1
20090241956 Baker, Jr. et al. Oct 2009 A1
20090241957 Baker, Jr. Oct 2009 A1
20090241958 Baker, Jr. Oct 2009 A1
20090241962 Jafari et al. Oct 2009 A1
20090247849 McCutcheon et al. Oct 2009 A1
20090247853 Debreczeny Oct 2009 A1
20090247891 Wood Oct 2009 A1
20090259135 Stasz Oct 2009 A1
20090301486 Masic Dec 2009 A1
20090301487 Masic Dec 2009 A1
20090301490 Masic Dec 2009 A1
20090301491 Masic et al. Dec 2009 A1
20090308394 Levi Dec 2009 A1
20100006098 McGinnis et al. Jan 2010 A1
20100008466 Balakin Jan 2010 A1
20100011307 Desfossez et al. Jan 2010 A1
20100024820 Bourdon Feb 2010 A1
20100051026 Graboi Mar 2010 A1
20100051029 Jafari et al. Mar 2010 A1
20100065055 Morris et al. Mar 2010 A1
20100065057 Berthon-Jones Mar 2010 A1
20100069761 Karst et al. Mar 2010 A1
20100071689 Thiessen Mar 2010 A1
20100071692 Porges Mar 2010 A1
20100071695 Thiessen Mar 2010 A1
20100071696 Jafari Mar 2010 A1
20100071697 Jafari et al. Mar 2010 A1
20100078017 Andrieux et al. Apr 2010 A1
20100078019 Rittner et al. Apr 2010 A1
20100078026 Andrieux et al. Apr 2010 A1
20100081119 Jafari et al. Apr 2010 A1
20100081955 Wood, Jr. et al. Apr 2010 A1
20100083968 Wondka et al. Apr 2010 A1
20100137380 Maybaum Jun 2010 A1
20100137723 Patangay et al. Jun 2010 A1
20100137729 Pierry et al. Jun 2010 A1
20100137730 Hatlestad Jun 2010 A1
20100139660 Adahan Jun 2010 A1
20100145165 Merry Jun 2010 A1
20100145201 Westbrook et al. Jun 2010 A1
20100147303 Jafari et al. Jun 2010 A1
20100152553 Ujhazy et al. Jun 2010 A1
20100152560 Turcott Jun 2010 A1
20100170512 Kuypers et al. Jul 2010 A1
20100174200 Wood et al. Jul 2010 A1
20100174207 Lee et al. Jul 2010 A1
20100180898 Schneider et al. Jul 2010 A1
20100186741 Aylsworth et al. Jul 2010 A1
20100186742 Sherman et al. Jul 2010 A1
20100186743 Kane et al. Jul 2010 A1
20100186744 Andrieux Jul 2010 A1
20100191076 Lewicke et al. Jul 2010 A1
20100191137 Brada et al. Jul 2010 A1
20100192094 Jeha et al. Jul 2010 A1
20100198086 Kuo et al. Aug 2010 A1
20100198289 Kameli et al. Aug 2010 A1
20100199991 Koledin Aug 2010 A1
20100210924 Parthasarathy et al. Aug 2010 A1
20100212675 Walling et al. Aug 2010 A1
20100218764 Kwok et al. Sep 2010 A1
20100218765 Jafari et al. Sep 2010 A1
20100218766 Milne Sep 2010 A1
20100218767 Jafari et al. Sep 2010 A1
20100218773 Thornton Sep 2010 A1
20100222692 McCawley et al. Sep 2010 A1
20100222693 Eriksen et al. Sep 2010 A1
20100224190 Tilley et al. Sep 2010 A1
20100228133 Averina et al. Sep 2010 A1
20100228134 Martikka et al. Sep 2010 A1
20100229863 Enk Sep 2010 A1
20100234750 Ariav et al. Sep 2010 A1
20100236553 Jafari Sep 2010 A1
20100236554 Prete Sep 2010 A1
20100236555 Jafari Sep 2010 A1
20100241009 Petkie Sep 2010 A1
20100242961 Mougel et al. Sep 2010 A1
20100242965 Berthon-Jones Sep 2010 A1
20100249549 Baker, Jr. et al. Sep 2010 A1
20100249630 Droitcour et al. Sep 2010 A1
20100249631 Aoki et al. Sep 2010 A1
20100249632 Lee et al. Sep 2010 A1
20100249633 Droitcour et al. Sep 2010 A1
20100252037 Wondka et al. Oct 2010 A1
20100252039 Cipollone et al. Oct 2010 A1
20100252040 Kapust et al. Oct 2010 A1
20100252041 Kapust et al. Oct 2010 A1
20100252042 Kapust et al. Oct 2010 A1
20100252043 Freitag Oct 2010 A1
20100256463 Greenwald et al. Oct 2010 A1
20100258116 Federspiel et al. Oct 2010 A1
20100258124 Madaus et al. Oct 2010 A1
20100258126 Ujhazy et al. Oct 2010 A1
20100258127 Hk Oct 2010 A1
20100262032 Freeberg Oct 2010 A1
20100262035 Subramanian Oct 2010 A1
20100275920 Tham et al. Nov 2010 A1
20100282251 Calluaud et al. Nov 2010 A1
20100282259 Figueiredo et al. Nov 2010 A1
20100288279 Seiver et al. Nov 2010 A1
20100288283 Campbell et al. Nov 2010 A1
20100292544 Sherman et al. Nov 2010 A1
20100300446 Nicolazzi et al. Dec 2010 A1
20100324438 Ni et al. Dec 2010 A1
20100331639 O'Reilly Dec 2010 A1
20100331715 Addison et al. Dec 2010 A1
20110009763 Levitsky et al. Jan 2011 A1
20110011400 Gentner et al. Jan 2011 A1
20110017214 Tehrani Jan 2011 A1
20110023878 Thiessen Feb 2011 A1
20110023879 Vandine et al. Feb 2011 A1
20110023880 Thiessen Feb 2011 A1
20110023881 Thiessen Feb 2011 A1
20110029910 Thiessen Feb 2011 A1
20110036352 Estes et al. Feb 2011 A1
20110041847 Cosic Feb 2011 A1
20110041849 Chen et al. Feb 2011 A1
20110041850 Vandine Feb 2011 A1
20110067698 Zheng et al. Mar 2011 A1
20110092839 Alshaer et al. Apr 2011 A1
20110126829 Carter et al. Jun 2011 A1
20110126832 Winter et al. Jun 2011 A1
20110126834 Winter et al. Jun 2011 A1
20110126835 Winter et al. Jun 2011 A1
20110126836 Winter et al. Jun 2011 A1
20110126837 Winter et al. Jun 2011 A1
20110128008 Carter Jun 2011 A1
20110132361 Sanchez Jun 2011 A1
20110132362 Sanchez Jun 2011 A1
20110132364 Ogilvie et al. Jun 2011 A1
20110132365 Patel et al. Jun 2011 A1
20110132366 Ogilvie et al. Jun 2011 A1
20110132367 Patel Jun 2011 A1
20110132368 Sanchez et al. Jun 2011 A1
20110132369 Sanchez Jun 2011 A1
20110132371 Sanchez et al. Jun 2011 A1
20110133936 Sanchez et al. Jun 2011 A1
20110138308 Palmer et al. Jun 2011 A1
20110138309 Skidmore et al. Jun 2011 A1
20110138311 Palmer Jun 2011 A1
20110138315 Vandine et al. Jun 2011 A1
20110138323 Skidmore et al. Jun 2011 A1
20110146681 Jafari et al. Jun 2011 A1
20110146683 Jafari et al. Jun 2011 A1
20110154241 Skidmore et al. Jun 2011 A1
20110175728 Baker, Jr. Jul 2011 A1
20110196251 Jourdain et al. Aug 2011 A1
20110197884 Duff et al. Aug 2011 A1
20110208082 Madaus et al. Aug 2011 A1
20110209702 Vuong et al. Sep 2011 A1
20110209704 Jafari et al. Sep 2011 A1
20110209707 Terhark Sep 2011 A1
20110213215 Doyle et al. Sep 2011 A1
20110230780 Sanborn et al. Sep 2011 A1
20110249006 Wallace et al. Oct 2011 A1
20110259330 Jafari et al. Oct 2011 A1
20110259332 Sanchez et al. Oct 2011 A1
20110259333 Sanchez et al. Oct 2011 A1
20110265024 Leone et al. Oct 2011 A1
20110265793 Haveri Nov 2011 A1
20110271960 Milne et al. Nov 2011 A1
20110273299 Milne et al. Nov 2011 A1
20110288431 Alshaer et al. Nov 2011 A1
20110313263 Wood et al. Dec 2011 A1
20120000467 Milne et al. Jan 2012 A1
20120000468 Milne et al. Jan 2012 A1
20120000469 Milne et al. Jan 2012 A1
20120000470 Milne et al. Jan 2012 A1
20120016252 Melker et al. Jan 2012 A1
20120029317 Doyle et al. Feb 2012 A1
20120029362 Patangay et al. Feb 2012 A1
20120030611 Skidmore Feb 2012 A1
20120037159 Mulqueeny et al. Feb 2012 A1
20120060841 Crawford, Jr. et al. Mar 2012 A1
20120071729 Doyle et al. Mar 2012 A1
20120090611 Graboi et al. Apr 2012 A1
20120096381 Milne et al. Apr 2012 A1
20120101399 Henderson Apr 2012 A1
20120123219 Georgiev et al. May 2012 A1
20120133519 Milne et al. May 2012 A1
20120136222 Doyle et al. May 2012 A1
20120136270 Leuthardt et al. May 2012 A1
20120137249 Milne et al. May 2012 A1
20120137250 Milne et al. May 2012 A1
20120167885 Masic et al. Jul 2012 A1
20120185792 Kimm et al. Jul 2012 A1
20120197578 Vig et al. Aug 2012 A1
20120197580 Vij et al. Aug 2012 A1
20120211008 Perine et al. Aug 2012 A1
20120216809 Milne et al. Aug 2012 A1
20120216810 Jafari et al. Aug 2012 A1
20120216811 Kimm et al. Aug 2012 A1
20120226444 Milne Sep 2012 A1
20120247471 Masic et al. Oct 2012 A1
20120272960 Milne Nov 2012 A1
20120272961 Masic et al. Nov 2012 A1
20120272962 Doyle et al. Nov 2012 A1
20120277616 Sanborn et al. Nov 2012 A1
20120279501 Wallace et al. Nov 2012 A1
20120304995 Kauc Dec 2012 A1
20120304997 Jafari et al. Dec 2012 A1
20130000644 Thiessen Jan 2013 A1
20130006133 Doyle et al. Jan 2013 A1
20130006134 Doyle et al. Jan 2013 A1
20130008443 Thiessen Jan 2013 A1
20130025596 Jafari et al. Jan 2013 A1
20130025597 Doyle et al. Jan 2013 A1
20130032149 Robinson Feb 2013 A1
20130032151 Adahan Feb 2013 A1
20130042869 Andrieux et al. Feb 2013 A1
20130047983 Andrieux et al. Feb 2013 A1
20130047989 Vandine et al. Feb 2013 A1
20130053717 Vandine et al. Feb 2013 A1
20130074844 Kimm et al. Mar 2013 A1
20130081536 Crawford, Jr. et al. Apr 2013 A1
20130104896 Kimm et al. May 2013 A1
20130146055 Jafari et al. Jun 2013 A1
20130152923 Andrieux et al. Jun 2013 A1
20130152934 Mulqueeny Jun 2013 A1
20130158370 Doyle et al. Jun 2013 A1
20130159912 Baker, Jr. Jun 2013 A1
20130167842 Jafari et al. Jul 2013 A1
20130167843 Kimm et al. Jul 2013 A1
20130186397 Patel Jul 2013 A1
20130186400 Jafari et al. Jul 2013 A1
20130186401 Jafari et al. Jul 2013 A1
20130192599 Nakai et al. Aug 2013 A1
20130220324 Jafari et al. Aug 2013 A1
20130233314 Jafari et al. Sep 2013 A1
20130233319 Winter et al. Sep 2013 A1
20130239038 Skidmore et al. Sep 2013 A1
20130239967 Jafari et al. Sep 2013 A1
20130255682 Jafari et al. Oct 2013 A1
20130255685 Jafari et al. Oct 2013 A1
20130276788 Masic Oct 2013 A1
20130283197 Skidmore Oct 2013 A1
20130284173 Masic et al. Oct 2013 A1
20130327331 Bourdon Dec 2013 A1
20130333697 Carter et al. Dec 2013 A1
20130333703 Wallace et al. Dec 2013 A1
20130338514 Karst et al. Dec 2013 A1
20130345532 Doyle et al. Dec 2013 A1
20140034056 Leone et al. Feb 2014 A1
20140123979 Doyle et al. May 2014 A1
20140182590 Platt et al. Jul 2014 A1
20140224250 Sanchez et al. Aug 2014 A1
20140251328 Graboi et al. Sep 2014 A1
20140261409 Dong et al. Sep 2014 A1
20140261410 Sanchez et al. Sep 2014 A1
20140261424 Doyle et al. Sep 2014 A1
20140276176 Winter Sep 2014 A1
20140373845 Dong Dec 2014 A1
20150034082 Kimm et al. Feb 2015 A1
20150045687 Nakai et al. Feb 2015 A1
Foreign Referenced Citations (25)
Number Date Country
982043 Mar 2000 EP
1491227 Dec 2004 EP
858352 Jan 2005 EP
1515767 Aug 2009 EP
WO 9014852 Dec 1990 WO
WO 9214505 Sep 1992 WO
WO 9308857 May 1993 WO
WO 199715343 May 1997 WO
WO 9812965 Apr 1998 WO
WO 199951292 Oct 1999 WO
WO 199962580 Dec 1999 WO
WO 200010634 Mar 2000 WO
WO 200078380 Dec 2000 WO
WO 0100264 Jan 2001 WO
WO 0100265 Jan 2001 WO
WO 200174430 Oct 2001 WO
WO 2002028460 Apr 2002 WO
WO 2002032488 Apr 2002 WO
WO 2003008027 Jan 2003 WO
WO 04000114 Dec 2003 WO
WO 04047621 Jun 2004 WO
WO 2005004780 Jan 2005 WO
WO 0785110 Aug 2007 WO
WO 2007102866 Sep 2007 WO
WO 2007145948 Dec 2007 WO
Non-Patent Literature Citations (6)
Entry
Dong, Feng Dan, “Advanced Control Algorithms for Discrete Linear Repetitive Processes in Self-servowriting of Hard Disk Drives”, Disseration, Univ. of California, Berkeley, Spring 2011, 143 pgs.
7200 Series Ventilator, Options, and Accessories: Operator's Manual. Nellcor Puritan Bennett, Part No. 22300 A, Sep. 1990, pp. 1-196.
7200 Ventilatory System: Addendum/Errata. Nellcor Puritan Bennett, Part No. 4-023576-00, Rev. A, Apr. 1988, pp. 1-32.
800 Operator's and Technical Reference Manual. Series Ventilator System, Nellcor Puritan Bennett, Part No. 4-070088-00, Rev. L, Aug. 2010, pp. 1-476.
840 Operator's and Technical Reference Manual. Ventilator System, Nellcor Puritan Bennett, Part No. 4-075609-00, Rev. G, Oct. 2006, pp. 1-424.
Carteaux, G. et al., “An Algorithm to Adjust the Percentage of Assistance in PAV+ Based on an Estimation of the Patient's Respiratory Effort”, Am. J. Respir. Crit. Care Med. 181, 2010, 1 pg. abstract.
Related Publications (1)
Number Date Country
20130284172 A1 Oct 2013 US