Patent Grant
10864336
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, such as mandatory ventilation modes and assist control ventilation modes.
This disclosure describes systems and methods for providing novel systems and methods for trigging inspiration. In particular, this disclosure describes systems and methods for triggering ventilation utilizing a digital sample counting trigger mode.
In part, this disclosure describes a method for ventilating a patient with a ventilator. The method includes:
monitoring a physiological parameter of the patient based on one or more received sensor measurements;
calculating a first derivative and a second derivative of the physiological parameter for a first sample period;
selecting a first trigger count threshold and a first level based on the second derivative;
updating a sample count to form a first updated sample count for the first sample period based on first comparison results from at least one of the following:
comparing the first updated sample count to the first trigger count threshold; and
triggering inspiration based on a first result of the comparing of the first updated sample count to the first trigger count threshold.
The disclosure further describes a ventilator system that includes: a pressure generating system, one or more sensors, a parameter module, a derivative module, a threshold module, a counter module, a compare module, and/or a trigger module. The pressure generating system generates a flow of breathing gas. The one or more sensors are operatively coupled to at least one of the pressure generating system, the patient, and a ventilation tubing system that delivers the flow of breathing gas from the pressure generating system to the patient. The one or more sensors generate sensor output for each sample period. The parameter module monitors a physiological parameter from the sensor output for each sample period. The derivative module calculates a first derivative and/or a second derivative for the physiological parameter for each sample period. The threshold module selects a trigger count threshold and a level based on the second derivative for each sample period. The counter module updates a sample count based on the first derivative, the second derivative, the level, and/or the trigger count threshold for each sample period to form an updated sample count. The compare module compares a selected trigger count threshold to an updated sample count for a same sample period. The trigger module triggers inspiration based on a receipt of a first result from the compare module.
The disclosure additionally describes a computer-readable medium having computer-executable instructions for performing a method for ventilating a patient with a ventilator. The method includes:
monitor an estimated patient effort of the patient based on received sensor measurements;
calculate a first derivative and a second derivative of the estimated patient effort for a first sample period;
select a first trigger count threshold and a first level based on the first derivative and the second derivative;
update a sample count to form a first updated sample count for the first sample period based on a comparison result from comparing the second derivative to the first level;
compare the first updated sample count to the first trigger count threshold; and
trigger inspiration based on a first result from the comparing of the first updated sample count to the first trigger count threshold.
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 in the drawings.
It is to be understood that both the foregoing general description and the following detailed description are explanatory and are intended to provide further explanation of the disclosure as claimed.
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 disclosure in any manner, which scope shall be based on the claims.
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 flow rates. Ventilators capable of operating independently of external sources of pressurized air are also available.
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, breath types, and/or settings have been created to provide better ventilation for patients in various different scenarios, such as mandatory ventilation modes and assist control ventilation modes. Assist control modes (also referred to herein as “spontaneous modes”) allow a spontaneously breathing patient to trigger inspiration during ventilation. In a spontaneous mode of ventilation, the ventilator triggers inspiration upon the detection of patient demand to inhale and cycles or initiates expiration when a predetermined threshold is met or when a patient demand for exhalation is detected.
The response performance of a medical ventilator to a patient trigger from exhalation into inhalation and/or from inhalation into exhalation represents an important characteristic of a medical ventilator. A ventilator's inspiration trigger and/or exhalation cycle response impacts the patient's work of breathing and the overall patient-ventilator synchrony. The inspiration trigger and/or exhalation cycle response performance of a ventilator is a function of a patient's inspiratory behavior (breathing effort magnitude and timing characteristics) as well as the ventilator's gas delivery dynamics and flow control parameters (actuator response, dead bands, etc.).
Triggering delay time, cycling delay time, and asynchrony index are among key parameters that are used to measure the patient-ventilator synchrony. The asynchrony index is the ratio between the number of asynchronous event and the total respiratory rate. Miss-triggering is also considered as one of the factors that increases the patient-ventilator asynchrony index. Several different factors cause asynchrony events, such as variation in patient's breathing pattern, muscle strength, respiratory mechanics, ventilator performance, and ventilator characteristics.
In conventional flow triggering modes, a patient's inspiratory trigger is detected based on the magnitude of flow deviations generated by the patient's inspiratory effort. Recently, mechanical ventilator inspiration triggering and/or exhalation cycling improvements, such as triggering/cycling time delay reduction or ineffective breath detection have been developed. However, less attention has been paid to prevent undesired auto-triggered breath cycles caused by patient circuit vibrations or by humidification effects which agitate flow and pressure sensors/signals. Auto-triggering is more prevalent when a ventilator's triggering sensitivity value is set to a low value. One attempt to prevent auto-triggering is to change the triggering threshold until auto-triggering vanishes. However, a ventilator becomes less responsive to shallow breathes as the trigger threshold increases (the higher the trigger threshold, the larger a change in flow necessary to detect a patient trigger by the ventilator).
Further, missed inspiration triggering is particularly prevalent during the ventilation of chronic obstructive pulmonary disease patients (COPD). COPD patients demand another breath before they have fully exhaled. As a result, traditional flow triggering modes are not able to detect patient efforts even with the best optimized trigger thresholds.
Accordingly, the systems and methods described herein provide for an improved inspiration triggering and/or exhalation cycling. For example, improved inspiration triggering and/or exhalation cycling reduces or prevents auto-triggering even when the lowest trigger/cycle threshold is utilized. This new ventilator synchronization mechanism is referred to herein as the digital sample counting trigger mode (“DSCT mode”). While the DSCT mode is referred to herein as a mode, it may also be referred to as a triggering type, breath type, supplemental breath type, or supplemental mode because the DSCT mode is utilized in conjunction with or in addition to any spontaneous mode of ventilation running any suitable breath type for a spontaneous mode of ventilation. The DSCT mode improves ventilator synchrony by improving inspiration trigger and/or exhalation cycling detection. The DSCT mode detects weak patient efforts that could not have been previously detected by conventional flow inspiration triggering and/or exhalation cycling methods or systems. The DSCT mode utilizes the concavity theorem to characterize the data for each sample period to detect patient inspiration triggers and/or exhalation cycles. The concavity theorem can be expressed as follows:
The DSCT mode evaluates the signal of a derivative and/or second derivative of a physiological parameter for each sample period. If the signal of the physiological parameter meets one or more predetermine requirements for a predetermined number or count of consecutive sample periods, the DSCT mode detects a patient inspiration trigger and/or exhalation cycle. If the signal does not meet the one or more requirements, the count of sample periods is set to zero and the DSCT mode starts over and evaluates the signal from the physiological parameter for the next sample period.
The digital processing utilized by the DSCT mode provides for numerous advantages, such as fast detection, decreased asynchrony, and detection of patient conditions, such as COPD and ARDS. Conventional inspiration triggering and/or exhalation cycling modes, such as flow triggering, are all based on a continuous waveform crossing a predefined threshold, unlike the digital nature of the DSCT mode. The crossing of a continuous waveform may be very time consuming since the waveform must “continuously” decline below a preset trigger or cycle threshold regardless of when the patient initiated the trigger or cycle, unlike the sample counting of the DSCT mode. As such, conventional inspiration triggering and/or exhalation cycling modes require 300 ms or more to detect a patient trigger unlike the DSCT mode. The DSCT mode may detect a patient trigger and/or cycle in less than 70 milliseconds (ms) and in some embodiments, in 30 ms or less. Further, the DSCT mode prevents auto-triggers or auto-cycles from occurring by circuit noise even when the most sensitive triggering thresholds are utilized by the ventilator. Additionally, the DSCT mode can detect auto-positive end expiratory pressure (PEEP) before missing even one patient initiated inspiration trigger or exhalation cycle.
As such, the DSCT mode provides a way to detect digital samples (of any given measured or estimated pulmonary signal) that become dense or compressed in magnitude once the patient starts inhaling. Based on this detection, the ventilator delivers a breath once it identifies the acquired digital samples are compressed enough (in terms of magnitude) to be considered a patient effort or demand to inspire and/or exhale. Accordingly, the DSCT mode “characterizes” the compression/sparseness of digital samples taken from the estimated or measured patient pulmonary signal to detect the patient inhalation/exhalation demand to synchronize the mechanical ventilator breath delivery with patient inhalation/exhalation demand.
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 the patient interface 180 (shown as an endotracheal tube in
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, accumulator and/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 and/or through the inspiratory limb 132 according to prescribed ventilatory settings. The inspiratory module 104 is associated with and/or controls an inspiratory valve for controlling gas delivery to the patient 150 and/or gas delivery through the inspiratory limb 132. In some embodiments, inspiratory module 104 is configured to provide ventilation according to various ventilator modes, such as mandatory, spontaneous, and/or assist modes.
The expiratory module 108 is configured to release gases from the patient's lungs according to prescribed ventilatory settings. The 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
Sensors 107 may communicate with various components of ventilator 100, e.g., pneumatic system 102, other sensors 107, expiratory module 108, inspiratory module 104, processor 116, controller 110, extremum seeking module 105, parameter module 113, derivative module 111, trigger module 115, counter module 117, compare module 118, threshold module 119, and any other suitable components and/or modules. A module as used herein refers to memory, one or more processors, storage, and/or other components of the type commonly found in command and control computing devices. In one embodiment, sensors 107 generate output and send this output to pneumatic system 102, other sensors 107, expiratory module 108, inspiratory module 104, processor 116, controller 110, extremum seeking module 105, parameter module 113, derivative module 111, trigger module 115, counter module 117, compare module 118, threshold 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 inspiratory or expiratory 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. For example, in some embodiments, one or more sensors 107 may be located in an accumulator. 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 104, 108 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. Any sensory device useful for monitoring changes in measurable parameters during ventilatory treatment may be employed in accordance with embodiments described herein. For example, in some embodiments, the one or more sensors 107 of the ventilator 100 include an inspiratory flow sensor and an expiratory flow sensor.
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 by derivation according to the Equation of Motion or other known relationships from the monitored parameters.
The parameter module 113 monitors a physiological parameter of the patient for each sample period from sensor output from one or more sensors. The sample period as used herein refers to a discrete period of time in which the parameter module monitors a physiological parameter. In some embodiments, the sample period is a computation cycle for the ventilator 100. In some embodiments, the sample period is every 5 milliseconds (ms), 10 ms, 15 ms, 20 ms, 25 ms, or 30 ms. This list is exemplary only and is not meant to be limiting. Any suitable sample period for monitoring a physiological parameter of the patient may be utilized by the ventilator as would be understood by a person of skill in the art. In some embodiments, the parameter module 113 estimates and/or calculates the physiological parameter for monitoring based on the sensor output from one or more sensors. In other embodiments, parameter module 113 determines the physiological parameter for monitoring directly from the sensor output received from the one or more sensors. The physiological parameter may be any suitable physiological parameter for determining a patient initiated trigger as would be known by a person of skill in the art. In some embodiments, the physiological parameter is flow rate, net flow, rate of change in flow, pressure, rate of change in pressure, net pressure, patient effort or muscle pressure, estimated patient effort, estimated pressure, estimated flow, rate of change of patient effort, rate of change of estimated patient effort, and/or etc. This list is exemplary only and is not meant to be limiting.
In some embodiments, the parameter module 113 determines, calculates, and/or estimates the patient's inspiratory airway resistance, the expiratory airway resistance, the lung-thorax compliance, and the residual pressure. In some embodiments, the parameter module 113 estimates the patient's inspiratory airway resistance, the expiratory airway resistance, the lung-thorax compliance, and the residual pressure while the patient's respiratory muscles are fully relaxed, by fitting the measured flow onto the measured pressure at the mouth using a model of the patient's respiratory system. In additional embodiments, the parameter module 113 determines, estimates, or calculates the patient effort (also known as muscle pressure (Pmus)). In further embodiments, the parameter module 113 estimates the respiratory effort of the patient by utilizing a model of the respiratory system of the patient, the recursive least squares method, and the following estimated parameters: the patient's inspiratory airway resistance; the expiratory airway resistance; the lung-thorax compliance; and the residual pressure. In some embodiments, the parameter module 113 determines, estimates, and/or calculates a patient's flow rate, net flow, change in flow, pressure, change in pressure, net pressure, patient effort or muscle pressure directly from sensor output received from one or more sensors 107.
After determining the physiological parameter, the parameter module 113 may send the physiological parameter to any suitable component and/or module of the ventilator 100, such as the pneumatic system 102, expiratory module 108, inspiratory module 104, processor 116, controller 110, extremum seeking module 105, trigger module 115, counter module 117, compare module 118, derivative module 111, parameter module 113, and/or etc. In some embodiments, the parameter module 113 sends the physiological parameter to the derivative module 111.
The derivative module 111 calculates the first derivative (DX or {dot over (X)}) of the physiological parameter and/or calculates the second derivative (DXX or {umlaut over (X)}) of the physiological parameter. In additional embodiments, the derivative module 111 amplifies the first derivative (DX or {dot over (X)}) and/or amplifies the second derivative (DXX or {umlaut over (X)}) of the physiological parameter. “DX,” “{dot over (X)},” “{umlaut over (X)},” and “DXX” as utilized herein, can refer to the first and second derivatives and/or to the amplified first and second derivatives. In some embodiments, the derivative module 111 amplifies the first and second derivatives by an amplification factor of 5, 10, 20, 30, 40, 50, 60, 70, 80, and/or 90. This list is exemplary and is not meant to be limiting. Any suitable amplification factor may be utilized by the ventilator as would be known by a person of skill in the art. However, different amplification factors require different predetermined requirements and/or thresholds to be utilized during the DSCT mode. In additional embodiments, the first derivative is amplified by 50 and the second derivative is amplified by 10. In other embodiments, both the first derivative and the second derivative are amplified by 10.
In some embodiments, the derivative module 111 calculates the first and/or second derivative utilizing the following equations:
{dot over (X)}(i)=X(i)−X(i−1); and
{umlaut over (X)}(i)={dot over (X)}(i)−{dot over (X)}(i−1),
wherein {dot over (X)} is an amplified first derivative of a physiological parameter, {umlaut over (X)} is an amplified second derivative of the physiological parameter, i is an index that represents the state of the digital sampled signal, and X is the physiological parameter. In some embodiments the physiological parameter is directly measured and in other embodiments the physiological parameter is estimated by the derivative module 111 of the ventilator 100.
The derivative module 111 may send the first derivative, second derivative, and/or amplified first and second derivatives to other ventilator components, such as the pneumatic system 102, expiratory module 108, inspiratory module 104, processor 116, controller 110, extremum seeking module 105, trigger module 115, counter module 117, compare module 118, threshold module 119, parameter module 113, derivative module 111, and/or any other suitable components and/or modules of the ventilator 100. In some embodiments, the derivative module 111 may send the first and second derivatives or the amplified first and second derivatives to the counter module 117 and the trigger module 115.
The extremum seeking module 105 determines or finds maxima (peaks) and/or minima (valleys) of the first derivative and/or the second derivative. In some embodiments, the extremum seeking module 105 utilizes the extremum seeking algorithm to determine maxima and/or minima of the first derivative and/or second derivative. In some embodiments, the extremum seeking module 105 finds the maxima and/or the minima of the first derivative and/or the second derivative in real time. Further, the extremum seeking module 105 may keep the last maximum found for the first derivative and may buffer the maxima found on the second derivative during the exhalation phase. The extremum seeking module 105 may then keep track if the last extremum point found for the second derivative is a minimum or a maximum. Further, a predetermined number of the peaks (or maxima) of the second derivative are dynamically buffered to form an array of the second derivative maxima (DXX
The extremum seeking module 105 may send the maxima and/or minima of the first and/or second derivative and/or the array of the second derivative maxima to other ventilator components, such as the pneumatic system 102, expiratory module 108, inspiratory module 104, processor 116, controller 110, trigger module 115, counter module 117, compare module 118, threshold module 119, parameter module 113, derivative module 111, and/or any other suitable components and/or modules of the ventilator 100.
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 (e.g., sensor(s) 107, parameter module 113, and/or derivative module 111), 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 some embodiments, the operator interface 120 of the ventilator 100 includes a display 122 communicatively coupled to ventilator 100. Display 122 may provide various input screens, for receiving clinician input, and various display screens, for presenting useful information to the clinician. In embodiments, 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 some embodiments, the display 122 illustrates a trigger count threshold, a sample count, a level, a rate threshold, a ratio threshold, the predetermined requirements, a physiological parameter, a graph or waveform of the physiological parameter, a detected patient trigger, a counted sample, and/or any other information known, received, or stored by the ventilator 100.
In some embodiments, controller 110 includes 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 derivative module 111, a parameter module 113, a trigger module 115, a counter module 117, a compare module 118, and a threshold module 119 as illustrated in
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 threshold module 119 selects a trigger count threshold and a level based on the second derivative and/or the first derivative for each sample period. The threshold module 119 may receive the second derivative for each sample period from the derivative module 111. In some embodiments, the second derivative received by the threshold module 119 has been amplified by the derivative module 111. In other embodiments, the threshold module 119 receives the second derivative for each sample period from any suitable module or component of the ventilator 100.
In some embodiments, the threshold module 119 selects between a large (also referred to herein as rigid) and a small (also referred to herein as relaxed) trigger count threshold. The large trigger count threshold requires a larger number or a larger count of sample periods to meet a set of predetermined requirements before a trigger is detected than a small trigger count threshold requires. As such, the large trigger count threshold is a rigid threshold that requires more time to detect a patient trigger than the small trigger count threshold that takes less time to detect a patient trigger. For example, in some embodiments, the trigger count threshold is selected from one of the following groups of a large and a small trigger count threshold: 1 and 2; 1 and 3; 2 and 3; 2 and 4; 3 and 4; 3 and 6; 4 and 5; and 4 and 6. This list is not limiting. Any suitable group of a large and a small trigger count threshold may be utilized by the threshold module 119 as would be understood by a person of skill in the art. In some embodiments, the trigger count threshold is selected from a large and a small trigger count threshold of 2 and 4. In other embodiments, the trigger count threshold is selected from a large and a small trigger count threshold of 1 and 2.
In further embodiments, the threshold module 119 selects between a large and a small level. The large level requires a less negative second derivative to be present to detect a patient trigger than a small level requires. As such, the large level is a relaxed threshold because the second derivative has to be larger (or less negative) to detect a patient trigger than the small level threshold that requires a smaller (or more negative) patient derivative to detect a patient trigger. For example, in some embodiments, the level is selected from one of the following groups of a large and a small level: −3 and −8; −4 and −9; −5 and −10; −10 and −15; and −15 and −20. This list is not limiting. Any suitable group of a large and a small level may be utilized by the threshold module 119 as would be understood by a person of skill in the art. In some embodiments, the level is selected from a large level of −3 and a small level of −8.
The threshold module 119 determines a signal to noise ratio for the second derivative. The threshold module 119 compares the signal to noise ratio to a threshold ratio. If the threshold module 119 determines that the signal to noise ratio is greater than the ratio threshold based on the comparison, the threshold module 119 selects a small trigger count threshold and/or selects a large level. A small trigger count threshold and a large level allows the ventilator 100 running a DSCT mode to detect a patient trigger in a shorter amount of time and with less of a decrease in the physiological parameter than the selection of a large trigger count threshold and a small level. If the threshold module 119 determines that the signal to noise ratio is less than or equal to the ratio threshold based on the comparison, the threshold module 119 selects a large trigger count threshold and/or selects a small level. The selection of a large trigger count threshold and a small level by the threshold module 119 requires a longer amount of time and a larger decrease in the physiological parameter to detect a patient trigger by the ventilator 100 running a DSCT mode. In some embodiments, the ratio threshold is less than zero or less than −1. This list is exemplary only and is not meant to be limiting. Any suitable ratio threshold may be utilized by the ventilator 100 as would be known by a person of skill in the art. Further, the ratio may need to be adjusted based on age, weight, height, gender, ideal body weight, and/or disease state.
In some embodiments, the threshold module 119 sends the selected trigger count threshold and/or the selected level to any component and/or module of the ventilator 100, such as the pneumatic system 102, expiratory module 108, inspiratory module 104, processor 116, controller 110, extremum seeking module 105, trigger module 115, counter module 117, compare module 118, derivative module 111, parameter module 113, and/or etc. In some embodiments, the threshold module 119 sends the selected trigger count threshold to the counter module 117, the compare module 118 and/or the trigger module 115. In further embodiments, the threshold module 119 sends the selected level to the counter module 117.
The counter module 117 updates a sample count based on one or more of the first derivative, the second derivative, the level, and the trigger count threshold for each sample period to form an updated sample count. As such, the counter module 117 updates the sample count based on whether one or more predetermined requirements relating to the first derivative, the second derivative, the level, and the trigger count threshold have been met for each sample period. The list of predetermined requirements provided below is exemplary and is not meant to be limiting. As known by a person of skill in the art, any suitable predetermined requirement may be checked by the counter module 117 in order to determine whether or not to count a given sample period or to determine how to update a sample count for a giving sample period.
In some embodiments, the counter module 117 compares the selected trigger count threshold received from the threshold module 119 to the trigger count threshold received from the threshold module 119 for the previous sample period. The previous sample period is the sample period that occurred immediately before the current sample period or is the sample period currently being evaluated by the counter module 117. If the counter module 117 determines that the current trigger count threshold is not the same as the previous trigger count threshold, the counter module 117 updates the sample count to zero. In some embodiments, if the counter module 117 determines that the current trigger count threshold is the same as or is equivalent to the previous trigger count threshold, the counter module 117 updates the sample count (n) to n+1. In alternative embodiments, if the counter module 117 determines that the current trigger count threshold is the same as or is equivalent to the previous trigger count threshold, the counter module 117 checks one or more additional requirements before updating the sample count. In some embodiments, during an initial sample period (e.g., the first sample period of the DSCT mode run by the ventilator 100) when no previous sample period data exists, the counter module 117 automatically determines that the current trigger count threshold is not equivalent to the previous trigger count threshold. In alternative embodiments, during an initial sample period when no previous sample period data exists, the counter module 117 automatically determines that the current trigger count threshold is equivalent to the previous trigger count threshold or skips performing this requirement check altogether.
In some embodiments, the counter module 117 compares the first derivative calculated for the current sample period to a previous first derivative calculated during a pervious sample period. The counter module 117 may receive the current first derivative and the pervious second derivative from the derivative module 111. In some embodiments, the counter module 117 may receive the first and second derivatives from any suitable component or module of the ventilator 100. In further embodiments, the first and second derivatives are amplified.
If the counter module 117 determines that first derivative is equal to or more than the previous first derivative, the counter module 117 updates the sample count (n) to zero. In some embodiments, if the counter module 117 determines that first derivative is less than the previous first derivative, the counter module 117 updates the sample count (n) to n+1. In alternative embodiments, if the counter module 117 determines that first derivative is less than the previous first derivative, the counter module 117 checks one or more additional requirements before updating the sample count. In some embodiments, during an initial sample period (e.g., the first sample period of the DSCT mode run by the ventilator 100) when no previous sample period data exists, the counter module 117 automatically determines that the current first derivative is not less than the first derivative. In alternative embodiments, during an initial sample period when no previous sample period data exists, the counter module 117 automatically determines that the current first derivative is equal to or greater than the previous first derivative or skips performing this requirement check altogether.
In some embodiments, the counter module 117 compares the second derivative calculated for the current sample period to a previous second derivative calculate during a pervious sample period. The counter module may receive the current second derivative and the pervious second derivative from the derivative module 111.
If the counter module 117 determines that second derivative is equal to or more than the previous second derivative, the counter module 117 updates the sample count (n) to zero. In some embodiments, if the counter module 117 determines that second derivative is less than the previous second derivative, the counter module 117 updates the sample count (n) to n+1. In alternative embodiments, if the counter module 117 determines that second derivative is less than the previous second derivative, the counter module 117 checks one or more additional requirements before updating the sample count. In some embodiments, during an initial sample period (e.g., the second sample period of the DSCT mode run by the ventilator 100) when no previous sample period data exists, the counter module 117 automatically determines that the current second derivative is not less than the second derivative. In alternative embodiments, during an initial sample period when no previous sample period data exists, the counter module 117 automatically determines that the current first derivative is equal to or greater than the previous first derivative or skips performing this requirement check altogether.
In additional embodiments, the counter module 117 compares the array of maxima of the second derivative (DXX
In further embodiments, the counter module 117 compares the second derivative to the selected level for the current sample period. As discussed above, the second derivative may be an amplified second derivative. The counter module 117 may receive the selected level from the threshold module 119 and the second derivative from the derivative module 111. If the counter module 117 determines that second derivative is more than the level, the counter module 117 updates the sample count (n) to zero. In some embodiments, if the counter module 117 determines that second derivative is less than or equal to the level, the counter module 117 updates the sample count (n) to n+1. In alternative embodiments, if the counter module 117 determines that second derivative is less than or equal to the level, the counter module 117 checks one or more additional requirements before updating the sample count.
In additional embodiments, the counter module 117 compares a rate of change for the second derivative to a rate threshold. The counter module 117 and/or the parameter module 113 may calculate or determine the rate of change of the second derivative based on the current and one or more previous second derivatives. As such, in some embodiments, the counter module 117 receives the rate of change for the second derivative from the parameter module 113.
If the counter module 117 determines that rate of change is equal to or more than the rate threshold, the counter module 117 updates the sample count (n) to zero. In some embodiments, if the counter module 117 determines that the rate of change is less than the rate threshold, the counter module 117 updates the sample count (n) to n+1. In alternative embodiments, if the counter module 117 determines that the rate of change is less than the rate threshold, the counter module 117 checks one or more additional requirements before updating the sample count. In some embodiments, during an initial sample period (e.g., the second sample period of the DSCT mode run by the ventilator 100) when no previous sample period data exists, the counter module 117 automatically determines that the rate of change is equal to or more than the rate threshold. In alternative embodiments, during an initial sample period when no previous sample period data exists, the counter module 117 automatically determines that the rate of change is less than the rate threshold or skips performing this requirement check altogether.
The rate threshold may be input or selected by the clinician. In other embodiments, the rate threshold is automatically selected by the ventilator based on one or more patient parameters (e.g., ideal body weight, height, weight, age, disease condition, and/or etc.) and/or physiological parameters (e.g., flow, pressure, tidal volume, heart rate, and/or etc.). In some embodiments, the rate threshold is the Lipschitz constant. In some embodiments, the rate threshold is less than 70 cm of H2O per second, 60 cm of H2O per second, 50 cm of H2O per second, 40 cm of H2O per second, or 30 cm of H2O per second. This list is exemplary only and is not meant to be limiting. Any suitable rate threshold may be utilized by the ventilator 100 as would be known by a person of skill in the art. Further, the ratio may need to be adjusted based on the patient's parameters, such as age, weight, height, gender, ideal body weight, and/or disease state.
In some embodiments, the counter module 117 updates the sample count to n+1 only when all of the predetermined requirements discussed above (e.g., the trigger count threshold is equivalent to the previous trigger count threshold, the first derivative is less than the previous first derivative, the second derivative is less than the previous second derivative, the second derivative is less than or equal to the level, and the second derivative's rate of change is not too large) for the counter module 117 are met. In other embodiments, the counter module 117 updates the sample count to n+1 when a select combination of the predetermined requirements listed above is met. In additional embodiments, the counter module 117 updates the sample count to zero when any one of the predetermined requirements discussed above for the counter module 117 are not met. In other embodiments, the counter module 117 updates the sample count to zero when a select combination of the predetermined requirements listed above are not met.
The counter module 117 may send the updated sample count to any suitable component or module of the ventilator 100, such as the pneumatic system 102, expiratory module 108, inspiratory module 104, processor 116, controller 110, extremum seeking module 105, trigger module 115, threshold module 119, compare module 118, parameter module 113, derivative module 111, and/or etc. In some embodiments, the counter module 117 sends the updated sample count to the compare module 118.
The compare module 118 compares a selected trigger count threshold to an updated sample count for a same sample period. The compare module 118 may receive the selected trigger count threshold and the updated sample count from any suitable ventilator module or component, such as the pneumatic system 102, extremum seeking module 105, expiratory module 108, inspiratory module 104, processor 116, controller 110, trigger module 115, threshold module 119, counter module 117, parameter module 113, derivative module 111, and/or etc. In some embodiments, the compare module 118 receives the selected trigger count threshold from the threshold module 119 and receives the updated sample count from the counter module 117. If the compare module 118 determines that the updated sample count is not equal to the selected trigger count threshold, then the compare module 118 waits for the next updated sample count and the next selected trigger count threshold for the next sample period. The next sample period is the sample period immediately following the current sample period. Further, in some embodiments, if the compare module 118 determines that the updated sample count is not equal to the selected trigger count threshold, the compare module 118 does not send any information to the trigger module 115. In other embodiments, if the compare module 118 determines that the updated sample count is not equal to the selected trigger count threshold, the compare module 118 sends a second result to the trigger module 115. The second result may be instructions and/or a command to not trigger inspiration or to continue exhalation. In other embodiments, the second results may be a notification that the updated sample count is not equal to the selected trigger count threshold. If the compare module 118 determines that the updated sample count is equal to the selected trigger count threshold, the compare module 118 may send a first result to the trigger module 115. The first result may be instructions and/or a command to trigger inspiration and/or to end expiration. In alternative embodiments, the first result may be a notification that the updated sample count is equal to the selected trigger count threshold. In other embodiments, the compare module 118 sends the first or second result to any suitable component or module of the ventilator 100, such as the pneumatic system 102, expiratory module 108, inspiratory module 104, processor 116, controller 110, extremum seeking module 105, trigger module 115, threshold module 119, counter module 117, parameter module 113, derivative module 111, and/or etc.
Ventilators 100, depending on their mode of operation, may trigger automatically and/or in response to a detected change in a ventilator 100 and/or physiological parameter. The trigger module 115 triggers inspiration based on a receipt of a first result. In some embodiments, the first result is received by the trigger module 115 from the compare module 118. In alternative embodiments, the first result is received by the trigger module 115 from another component or module of the ventilator 100.
To prevent apnea in the event that a patient trigger is not detected by the DSCT mode of the ventilator 100, the trigger module 115 also triggers inspiration after a predetermined amount exhalation time. Accordingly, the predetermined amount of exhalation time is also known as an apnea interval in some ventilators. For example, the trigger module 115 will automatically trigger an inspiration after 20 seconds, 30 seconds, or 60 seconds of exhalation time. In some embodiments, the predetermined amount of time is determined by the clinician and/or ventilator 100 based on whether the patient 150 is an infant, child, adult, male, female, and/or suffering from a specific disease state.
The trigger module 115 triggers inspiration by sending instructions and/or a command to a pneumatic system 102, an expiratory module 108, an inspiratory module 104, a processor 116, and/or a controller 110. The instructions and/or commands cause the one or more ventilator components and/or modules to change the delivered flow and/or pressure and to adjust the valves as needed to trigger inspiration.
In some embodiments, the trigger module 115 receives a second result. In some embodiments, the second result is received by the trigger module 115 from the compare module 118. In alternative embodiments, the second result is received by the trigger module 115 from another component or module of the ventilator 100. In some embodiments, if the trigger module 115 receives a second result, the trigger module 115 continues to deliver exhalation until the trigger module 115 receives a first result from another sample period.
The trigger module 115 delivers exhalation by sending instructions and/or a command to a pneumatic system 102, an expiratory module 108, an inspiratory module 104, a processor 116, and/or a controller 110. The instructions and/or commands cause the one or more ventilator components and/or modules to change the delivered flow and/or pressure and to adjust the valves as needed to deliver exhalation.
The ventilator 100 and its modules discussed above as illustrated in
In some embodiments, the ventilator during monitoring operation 202 determines, calculates, and/or estimates the patient's inspiratory airway resistance, the expiratory airway resistance, the lung-thorax compliance, and the residual pressure. In some embodiments, the ventilator during monitoring operation 202 estimates the patient's inspiratory airway resistance, the expiratory airway resistance, the lung-thorax compliance, and the residual pressure while the patient's respiratory muscles are fully relaxed, by fitting the measured flow onto the measured pressure at the mouth using a model of the patient's respiratory system. In additional embodiments, the ventilator during monitoring operation 202 estimates or calculates the patient effort (also known as muscle pressure (Pmus)) or the rate of change of the patient effort ({dot over (P)}mus). In further embodiments, the ventilator during monitoring operation 202 estimates the respiratory effort of the patient by utilizing a model of the respiratory system of the patient, the recursive least squares method, and the following estimated parameters: the patient's inspiratory airway resistance; the expiratory airway resistance; the lung-thorax compliance; and the residual pressure. In some embodiments, the ventilator during monitoring operation 202 determines, estimates, and/or calculates a patient's flow rate, net flow, change in flow, pressure, change in pressure, net pressure, patient effort or muscle pressure from one or more sensor measurements. The monitoring operations 202 may be performed by inspiration module, processor, controller, pneumatic system, exhalation module, sensors, and/or parameter module of the ventilator.
Method 200 also includes a calculating operation 204. The ventilator during the calculating operation 204 calculates the first and/or second derivative of the physiological parameter for each sample period. In some embodiments, the ventilator during the calculating operation 204 performs an amplification operation 204a, as illustrated in
In some embodiments, the physiological parameter is an estimated patient effort and the ventilator during the calculating operation 204 calculates first and second derivatives of the estimated patient effort. In further embodiments, the ventilator during the calculating operation 204 amplifies the first and second derivatives of the estimated patient effort. The calculating operations 204 may be performed by the inspiration module, processor, controller, pneumatic system, exhalation module, parameter module, sensors, and/or derivative module of the ventilator. In some embodiments, the ventilator during calculating operation 204 calculates the first and/or second derivative utilizing the following equations:
{dot over (X)}(i)=X(i)−X(i−1); and
{umlaut over (X)}(i)={dot over (X)}(i)−{dot over (X)}(i−1),
wherein {dot over (X)} is an amplified first derivative of a physiological parameter, {umlaut over (X)} is an amplified second derivative of the physiological parameter, i is an index that represents the state of the digital sampled signal, and X is the physiological parameter.
Method 200 also includes an extremum seeking operation 205. The ventilator during the extremum seeking operation 205 finds or determines maxima and/or minima of the first derivative and/or the second derivative. In some embodiments, the ventilator during the extremum seeking operation 205 determines maxima and/or the minima of the first derivative and/or the second derivative in real time and/or utilizes an extremum seeking algorithm. In further embodiments, the ventilator during the extremum operation 205 keeps the last maximum found for the first derivative and buffers the maxima found on the second derivative during the exhalation phase. The extremum seeking operation 205 may then keep track if the last extremum point found for the second derivative is a minimum or a maximum. In additional embodiments, a predetermined number of the peaks (or maxima) of the second derivative are dynamically buffered to form an array of the second derivative maxima (DXX
Further, method 200 includes a selecting operation 206. The ventilator during the selecting operation 206 selects a trigger count threshold and/or a level based on the first derivative and/or the second derivative and/or their respective signals. In some embodiments, the selecting operation 206 includes a signal to noise operation 206a, a ratio determining operation 206b, a relaxed setting operation 206c, and/or a rigid setting operation 206d, as illustrated in
In some embodiments, the ventilator during the ratio determining operation 206b selects between a large and a small level. The large level requires a less negative second derivative to be present to detect a patient trigger than a small level requires. As such, the large level is a relaxed threshold because the descending second derivative can be larger (or less negative) to detect a patient trigger than the small level threshold.
In some embodiments, the ventilator during the ratio determining operation 206b selects between a large and a small trigger count threshold. The large trigger count threshold requires a larger number or a larger count of sample periods to meet a set of predetermined requirements before a trigger is detected by a ventilator performing method 200 than a small trigger count threshold requires. As such, the large trigger count threshold is a rigid threshold that causes the ventilator performing method 200 to require more time to detect a patient trigger than required by the ventilator when the small trigger count threshold is selected.
The selecting operations 206 may be performed by the inspiration module, processor, controller, pneumatic system, exhalation module, parameter module, sensors, derivative module and/or threshold module of the ventilator.
Additionally, method 200 includes an updating operation 208. During updating operation 208, the ventilator updates a sample count to form an updated sample count for each sample period based on one or more comparison results for each sample period. The one or more comparison results are a determination of whether or not one or more predetermined requirements relating to the first derivative, the second derivative, the level, and/or the trigger count threshold have been met for each sample period. In some embodiments, the updating operation 208 includes at least one of a first requirement operation 208a, a second requirement operation 208b, a third requirement operation 208c, a fourth requirement operation 208d, and/or a fifth requirement operation 208e. The ventilator during updating operation 208 does not update the sample count until at least one of a first predetermined requirement, a second predetermined requirement, a third predetermined requirement, a fourth predetermined requirement, and a the fifth predetermined requirement are checked during the performance of operations 208a, 208b, 208c, 208d, and/or 208e.
In some embodiments, a first predetermined requirement is that a current triggering threshold has to be equivalent to the previous triggering threshold. As such, in these embodiments, the ventilator during the first requirement operation 208a of updating operation 208 compares the trigger count threshold selected for a current sample period to a previous trigger count threshold selected in a previous sample period. If the ventilator during the first requirement operation 208a determines that the current trigger count threshold is not equal to the previous trigger count threshold, the ventilator updates the sample count to zero. In some embodiments, if the ventilator during the first requirement operation 208a determines that the current trigger count threshold is equal to the previous trigger count threshold, the ventilator updates the sample count (n) to n+1. In alternative embodiments, if the ventilator during the first requirement operation 208a determines that the current trigger count threshold is equal to the previous trigger count threshold, the ventilator determines if another predetermined requirement has been met or checks another comparison result.
In some embodiments, a second predetermined requirement is that the first derivative (also referred to as the current first derivative) for the current sample period is less than the first derivative (also referred to as the previous first derivative) calculated for the previous sample period. As such, in these embodiments, the ventilator during the second requirement operation 208b of updating operation 208 compares the current first derivative to a previous first derivative. If the ventilator during the second requirement operation 208b determines that the current first derivative is equal to or greater than the previous first derivative, the ventilator updates the sample count to zero. In some embodiments, if the ventilator during the second requirement operation 208b determines that the current first derivative is less than the previous first derivative, the ventilator updates the sample count (n) to n+1. In alternative embodiments, if the ventilator during the second requirement operation 208b determines that the current derivative is less than the previous first derivative, the ventilator determines if another predetermined requirement has been met or checks another comparison result.
In some embodiments, the second predetermined requirement is additionally or alternatively that the second derivative (also referred to as the current second derivative) for the current sample period is less than the second derivative (also referred to as the previous second derivative) calculated for the previous sample period. As such, in these embodiments, the ventilator during a second requirement operation 208b of updating operation 208 compares the current second derivative to a previous second derivative. If the ventilator during the second requirement operation 208b determines that the current second derivative is equal to or greater than the previous second derivative, the ventilator updates the sample count to zero. In some embodiments, if the ventilator during the second requirement operation 208b determines that the current second derivative is less than the previous second derivative, the ventilator updates the sample count (n) to n+1. In alternative embodiments, if the ventilator during the second requirement operation 208b determines that the current derivative is less than the previous second derivative, the ventilator determines if another predetermined requirement has been met or checks another comparison result.
In some embodiments, a third predetermined requirement is that the array of maxima of the second derivative is less than an array threshold (ψ). As such, in these embodiments, the ventilator during a third requirement operation 208c of updating operation 208 compares the array of the second derivative to an array threshold. The array threshold may be determined by the ventilator or selected or input by the operator. If the ventilator during the third requirement operation 208c determines that the array of maxima of second derivative is more than or equal to the array threshold, the ventilator updates the sample count (n) to zero. In some embodiments, if the ventilator during the third requirement operation 208c determines that the array of maxima of the second derivative is less than the array threshold, the ventilator updates the sample count (n) to n+1. In alternative embodiments, if the ventilator during the third requirement operation 208c determines that the array of maxima of the second derivative is less than the array threshold, the ventilator checks one or more additional requirements before updating the sample count. The use of the array threshold as a predetermined requirement prevents or reduces auto triggering (also referred to as false triggering) caused by patient circuit vibration and/or noise. In alternative embodiments, the third requirement operation 208c utilizes an array of minima of the second derivative instead of the array of maxima.
In some embodiments, a fourth predetermined requirement is that the second derivative for the current sample period is less than the selected level. As such, in these embodiments, the ventilator during a fourth requirement operation 208d of updating operation 208 compares the current second derivative to the level selected for the same sample period. If the ventilator during the fourth requirement operation 208d determines that the current second derivative is greater than the selected level, the ventilator updates the sample count to zero. In some embodiments, if the ventilator during the fourth requirement operation 208d determines that the current second derivative is less than or equal to the level, the ventilator updates the sample count (n) to n+1. In alternative embodiments, if the ventilator during the fourth requirement operation 208d determines that the current derivative is less than or equal to the level, the ventilator determines if another predetermined requirement has been met or checks another comparison result.
In some embodiments, a fifth predetermined requirement is that a calculated rate of change for the second derivative for the current sample period is less than a rate threshold. As such, in these embodiments, the ventilator during a fifth requirement operation 208e of updating operation 208 compares a calculated rate of change for the second derivative to a rate threshold. In some embodiments, the ventilator during the fifth requirement operation 208e calculates a rate of change for the current second derivative. In other embodiments, the ventilator during monitoring operation 202 and/or calculating operation 204 calculates the rate of change for the current second derivative. In additional embodiments, the rate threshold is the Lipschitz constant. If the ventilator during the fifth requirement operation 208e determines that the current second derivative is equal to or greater than the rate threshold, the ventilator updates the sample count to zero. In some embodiments, if the ventilator during the fifth requirement operation 208e determines that the current second derivative is less than the rate threshold, the ventilator updates the sample count (n) to n+1. In alternative embodiments, if the ventilator during the fifth requirement operation 208e determines that the current derivative is less than the rate threshold, the ventilator determines if another predetermined requirement has been met or checks another comparison result.
In some embodiments, the ventilator during updating operation 208 requires that each of the first predetermined requirement, the second predetermined requirement, the third predetermined requirement, the fourth predetermined requirement, and the fifth predetermined requirement are met to update the sample count to n+1. In other embodiments, the ventilator during updating operation 208 requires that the fourth requirement be met to update the sample count to n+1. In some embodiments, the ventilator during updating operation 208 updates a sample count to zero if any one of the first predetermined requirement, the second predetermined requirement, the third predetermined requirement, the fourth predetermined requirement, and the fifth predetermined requirement are not met. In other embodiments, the ventilator during updating operation 208 updates the sample count to zero if fourth requirement is not met. The updating operations 208 may be performed by the inspiration module, processor, controller, pneumatic system, exhalation module, parameter module, sensors, derivative module threshold module and/or counter module of the ventilator.
Next, method 200 includes a comparing operation 210. During the comparing operation 210, the ventilator compares the updated sample count for the current sample period to the trigger count threshold for the current sample period. If the ventilator determines during the comparing operation 210 that the updated sample count is not equal to the trigger count threshold (also referred to herein as a second result), the ventilator performs monitoring operation 202 for the next sample period. If the ventilator determines during the comparing operation 210 that the updated sample count is equal to the trigger count threshold (also referred to herein as a first result), the ventilator performs triggering operation 212. The comparing operations 210 may be performed by the processor, controller, pneumatic system, and/or compare module of the ventilator.
As illustrated in
In other 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 a trigger count threshold, a sample count, a level, a rate threshold, a ratio threshold, the predetermined requirements, a physiological parameter, a graph or waveform of the physiological parameter, a detected patient trigger, a counted sample, and/or any other information known, received, or stored by the ventilator.
While method 200 is described with regards to triggering inspiration utilizing the DSCT mode, the same principles could be applied for cycling exhalation utilizing the DSCT mode by using different predetermined requirement and threshold values as would be known and understood by a person of skill in the art. For example, the DSCT mode detects cycling by detecting when the digital samples become almost equal and flat in their magnitude (on a plateau waveform) at the end of inhalation.
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. These embodiments include performing or repeatedly performing based on stored instructions the operations disclosed in method 200 above and/or as illustrated in
Example 1 illustrates an embodiment of an algorithm utilized by method 200 or by the ventilator 100 to perform DSCT mode. The following list of equations and parameters are exemplary only and are not meant to be limiting.
The example algorithm employs the first and second derivatives ({dot over (X)} and {umlaut over (X)}) of the signal X (e.g., estimated patient effort) in real time, amplifies them by an amplification factor K{dot over (X)}=50 and K{umlaut over (X)}=10 (respectively) and performs signal processing as described below. The triggering algorithm uses an extremum seeking subsystem which detects the minima and maxima of {dot over (X)} and {umlaut over (X)} signals in real time. The algorithm keeps the last maximum found on the first derivative signal {dot over (X)}max and buffers the maxima found on the second derivative signal during exhalation phase. A flag is employed to show the final extremum point found on the second derivative is a minimum or maximum as shown in EQUATION #1 below:
Furthermore, all the peaks of the second derivative signal {umlaut over (X)}Max during patient respiratory signal observation are dynamically buffered in an array D{umlaut over (X)}
D{umlaut over (X)}
In other words, D{umlaut over (X)}
NetFlow≤0.5×PeakNetFlow EQ #3
where PeakNetFlow is the first peak found on the NetFlow (qN) signal after it reaches 3 Lpm during exhalation phase. The net instantaneous flow of gas into the patient tubing system, qN, is defined in Equation #4 as follows:
qN=qinsp−qE, EQ #4
where qinsp and qE are the raw flow reading of the inspiratory flow sensor, and the unfiltered value of the flow passing through the exhalation port. All flow readings are expressed in liters per second (lps). In some instances, a unit conversion is required to transform these flows from liters per minute (lpm) to lps, which is accomplished by dividing the lpm values by 60 to obtain flows expressed in lps.
Once the above condition is met, all the following parameters in the algorithm will be reset to their initial values as the following table and the algorithm starts verifying the other triggering conditions.
The last maximum found on the first derivative signal, the flag that shows whether the last maximum found on the second derivative signal was a Max or Min and the past extrema found on the second derivative signal will be used for signal/noise ratio estimation purposes. In the following algorithm, the inspiration occurs once the number of digital samples counted by a dynamic counter reaches a predefined value (SampleCountSize=N>0). Furthermore, the counter starts counting after the signal {umlaut over (X)} reaches a predefined sensitivity threshold (SampleCountStartLevel=L<0). The target sample size (N) and the sample counting starting level (L) dynamically alter inside the algorithm depending on the variation of the Signal/Noise ratio (S/R). The Signal/Noise ratio variation can be caused by several factors such as any thermo-dynamical changes that affect the fluid dynamics inside the patient tubing or any unwanted vibration of the patient circuit. The new method introduces a Signal/Noise ratio estimation algorithm. The output of this algorithm is a function of the signal's second derivative amplitude {umlaut over (X)}, slope and the array of the previous maxima (D{umlaut over (X)}
“i” is an index that represents the state of the digital sampled signal.
The SampleCountStartLevel (L1, L2), the SampleCountSize (N1, N2), and the boundaries on the maximum of the maxima of the {umlaut over (X)} i.e. (τ, ψ) mapped to the five inspiration sensitivity scales are defined in the following table:
The amplification factors of the {dot over (X)} and {umlaut over (X)} signals and the control design parameters are defined below in Table 3.
γ is the upper bound on the magnitude of the current sample of the second derivative signal. This boundary is a control design parameter. dv is a constant bound which represents the modulus of uniform continuity or Lipschitz continuity characteristics of the second derivative function. The Lipschitz characteristic of a function shows how fast it can change. In other words, for every pair of points on the waveform of this signal, the absolute value of the slope of the line connecting them is no greater than a definite real number dv.
The dv has been employed as a tuning design parameter in this algorithm to distinguish between noise and meaningful signal. The higher value dv has, the less likelihood is the sampled signal to be considered as noise. S/N(i)Flag an is index that shows if the estimated signal to noise ratio is big enough to characterize the triggering criteria. If the S/N(i)Flag=1 (in other words the signal/noise ratio is big enough), the algorithm will proceed with more relaxed triggering criteria (lower NSampleCountSize and higher LSampleCountStartLevel). The lower value of the NSampleCountSize and higher LSampleCountStartLevel represent the closest instance to the beginning of the neural inspiration. If the S/N(i)flag=0 (in other words the signal/noise ratio has not been considered not big enough) then algorithm proceeds with a rigid triggering criteria. However, the algorithm does not block triggering just because of this estimation; instead, the algorithm penalizes the triggering criteria by stiffening the triggering criteria (higher NSampleCountSize and lower LSampleCountStartLevel). These criteria dynamically change in the algorithm depending on the signal/noise ratio variation of the current sample S/N(i) and the amplitudes of the previous maximum points found on the second derivative signal. The target sample size (NSampleCountSize) will be restricted to a higher value (e.g. stiffer triggering condition) if the maximum of the previous maxima of the second derivative buffered in D{umlaut over (X)}
Max(D{umlaut over (X)}NSampleCountSize=N2N2>N1 EQ #6
Each time the signal/noise ratio criteria (e.g., S/N(i)flag) changes, the “SampleCounter” which counts the samples will reset.
Once the triggering criteria are determined, the algorithm passes through another threshold criteria that evaluates the initiation criteria of the DSCT (Digital Sample Counting Trigger) algorithm. This function is presented below as Equation #7:
This functionality has been introduced by the second part of above mentioned pseudo code. λ is the upper bound on the magnitude of the last maximum of the first derivative signal. This boundary is a control design parameter that verifies if the rate of change of the main signal (speed) is small enough and the fluctuations of the main signal are stabilized enough to verify the patient respiratory demand and start the algorithm. As it was mentioned earlier, L is the dynamic threshold (SampleCountStartLevel) that the SampleCounter starts counting after the signal {umlaut over (X)} reaches this level. If the slope of the current sample of the second derivative signal becomes positive, the SampleCounter will be reset to zero.
Once the initiation criteria of the algorithm are evaluated, the algorithm evaluates the compaction of the magnitudes of the digital signal samples. Once the initiation criteria of the algorithm are evaluated, the algorithm passes through another threshold that evaluates the compaction of the magnitudes of the digital signal samples. This function is expressed as Equation #8 below and has been introduced in the inner loop condition of the second part of the above mentioned pseudo code:
ψ is the upper bound on the magnitude of the last three maxima of the second derivative signal. This boundary is a control design parameter that reflects the desired limitation on the acceleration of the variations on the main signal ({umlaut over (X)}) to be small enough, therefore, the fluctuations on this signal are stabilized enough to evaluate the compaction of the digital samples for a predetermined time interval.
The algorithm triggers a new breath if the number of samples counted in time interval Δt reaches the obtained target sample size N+1 before the slope of the current sample of the second derivative signal becomes positive (i.e. before a new minimum is found on the second derivative signal). This is the final triggering criterion that evaluates how squeeze are the magnitudes of the digital samples of the second derivative signal in the time interval Δt and determine breath delivery. The time interval Δt is equal to the target sample size number N obtained in the signal/noise ratio estimation algorithm multiplied by the ventilator fixed sampling time period (T) as illustrated in Equation #9 below:
Δt=N×T EQ #9
The upper bound on the differences of the magnitudes of the samples is dv, which represents the Lipschitz constant of the second derivative function in the design algorithm. This can be attributed to how fast a certain number of consecutive sampling points on the second derivative signal must change to be interpreted as the meaningful patient respiratory demand against noise. The more scattered are the magnitude of these samples, the less is the signal/noise ratio.
Once the above condition is met and the ventilator triggers a new breath, all the parameters in the above table will be reset to their initial values and the algorithm starts verifying the exhalation criteria.
Example 1 can be illustrated by the following pseudo code:
During every control cycle, the ventilator determines the subsequent value of the logical breath phase variable IE, according to the following rule:
IE(i)=(InspCondMe t(i) or !ExhCondMet (i))
and initial conditions:
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 disclosure.
This application is a continuation application and claims priority to U.S. patent application Ser. No. 14/460,615, now U.S. Pat. No. 9,808,591, filed Aug. 15, 2014, entitled “METHODS AND SYSTEMS FOR BREATH DELIVERY SYNCHRONIZATION,” which application is incorporated herein by reference in its entirety.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3575167 | Michielsen | Apr 1971 | A |
| 3584621 | Bird et al. | Jun 1971 | A |
| 3586021 | McGuinness | Jun 1971 | A |
| 3633576 | Gorsuch | Jan 1972 | A |
| 3662751 | Barkalow et al. | May 1972 | A |
| 3664370 | Warnow | May 1972 | A |
| 3669108 | Sundblom et al. | Jun 1972 | A |
| 3677267 | Richards | Jul 1972 | A |
| 3695263 | Kipling | Oct 1972 | A |
| 3741208 | Jonsson et al. | Jun 1973 | A |
| 3753436 | Bird et al. | Aug 1973 | A |
| 3756229 | Ollivier | Sep 1973 | A |
| 3768468 | Cox | Oct 1973 | A |
| 3789837 | Philips et al. | Feb 1974 | A |
| 3834382 | Lederman et al. | Sep 1974 | A |
| 3889669 | Weigl | Jun 1975 | A |
| 3896800 | Cibulka | Jul 1975 | A |
| 3903881 | Weigl | Sep 1975 | A |
| 3905362 | Eyrick et al. | Sep 1975 | A |
| 3908704 | Clement et al. | Sep 1975 | A |
| 3910261 | Ragsdale et al. | Oct 1975 | A |
| 3961627 | Ernst et al. | Jun 1976 | A |
| 3976052 | Junginger et al. | Aug 1976 | A |
| 3981301 | Warnow et al. | Sep 1976 | A |
| 4003377 | Dahl | Jan 1977 | A |
| 4029120 | Christianson | Jun 1977 | A |
| 4044763 | Bird | Aug 1977 | A |
| 4050458 | Friend | Sep 1977 | A |
| 4060078 | Bird | Nov 1977 | A |
| 4095592 | Delphia | Jun 1978 | A |
| 4121578 | Torzala | Oct 1978 | A |
| 4155357 | Dahl | May 1979 | A |
| 4164219 | Bird | Aug 1979 | A |
| 4197856 | Northrop | Apr 1980 | A |
| 4211221 | Schwanbom et al. | Jul 1980 | A |
| 4275722 | Sorensen | Jun 1981 | A |
| 4281651 | Cox | Aug 1981 | A |
| 4323064 | Hoenig et al. | Apr 1982 | A |
| 4340044 | Levy et al. | Jul 1982 | A |
| 4351344 | Stenzler | Sep 1982 | A |
| 4401115 | Monnier | Aug 1983 | A |
| 4401116 | Fry et al. | Aug 1983 | A |
| 4421113 | Gedeon et al. | Dec 1983 | A |
| 4444201 | Itoh | Apr 1984 | A |
| 4459982 | Fry | Jul 1984 | A |
| 4459983 | Beyreuther et al. | Jul 1984 | A |
| 4539984 | Kiszel et al. | Sep 1985 | A |
| 4554916 | Watt | Nov 1985 | A |
| 4558710 | Eichler | Dec 1985 | A |
| 4566450 | Brossman, Jr. | Jan 1986 | A |
| 4598706 | Darowski et al. | Jul 1986 | A |
| 4612928 | Tiep et al. | Sep 1986 | A |
| 4640277 | Meyer et al. | Feb 1987 | A |
| 4648407 | Sackner | Mar 1987 | A |
| 4702240 | Chaoui | Oct 1987 | A |
| 4721060 | Cannon et al. | Jan 1988 | A |
| 4752089 | Carter | Jun 1988 | A |
| 4757824 | Chaumet | Jul 1988 | A |
| 4766894 | Legrand et al. | Aug 1988 | A |
| 4790832 | Lopez | Dec 1988 | A |
| 4796618 | Garraffa | Jan 1989 | A |
| 4870961 | Barnard | Oct 1989 | A |
| 4889116 | Taube | Dec 1989 | A |
| 4921642 | LaTorraca | May 1990 | A |
| 4954799 | Kumar | Sep 1990 | A |
| 4981295 | Belman et al. | Jan 1991 | A |
| 4982735 | Yagata et al. | Jan 1991 | A |
| 5007420 | Bird | Apr 1991 | A |
| 5016626 | Jones | May 1991 | A |
| 5057822 | Hoffman | Oct 1991 | A |
| 5072737 | Goulding | Dec 1991 | A |
| 5074297 | Venegas | Dec 1991 | A |
| 5080093 | Raabe et al. | Jan 1992 | A |
| 5086767 | Legal | Feb 1992 | A |
| 5099837 | Russel, Sr. et al. | Mar 1992 | A |
| 5117818 | Palfy | Jun 1992 | A |
| 5127398 | Stone | Jul 1992 | A |
| 5129390 | Chopin et al. | Jul 1992 | A |
| 5134994 | Say | Aug 1992 | A |
| 5148802 | Sanders et al. | Sep 1992 | A |
| 5150291 | Cummings et al. | Sep 1992 | A |
| 5154167 | Hepburn | Oct 1992 | A |
| 5161525 | Kimm et al. | Nov 1992 | A |
| 5165397 | Arp | Nov 1992 | A |
| 5165398 | Bird | Nov 1992 | A |
| 5174284 | Jackson | Dec 1992 | A |
| 5195512 | Rosso | Mar 1993 | A |
| 5211170 | Press | May 1993 | A |
| 5235973 | Levinson | Aug 1993 | A |
| 5237987 | Anderson et al. | Aug 1993 | A |
| 5239995 | Estes et al. | Aug 1993 | A |
| 5259374 | Miller et al. | Nov 1993 | A |
| 5271389 | Isaza et al. | Dec 1993 | A |
| 5273032 | Borody | Dec 1993 | A |
| 5279549 | Ranford | Jan 1994 | A |
| 5299568 | Forare et al. | Apr 1994 | A |
| 5301921 | Kumar | Apr 1994 | A |
| 5303698 | Tobia et al. | Apr 1994 | A |
| 5303700 | Weismann et al. | Apr 1994 | A |
| 5307794 | Rauterkus et al. | May 1994 | A |
| 5316009 | Yamada | May 1994 | A |
| 5318017 | Ellison | Jun 1994 | A |
| 5318487 | Golen et al. | Jun 1994 | A |
| 5319540 | Isaza et al. | Jun 1994 | A |
| 5320093 | Raemer | Jun 1994 | A |
| 5322057 | Raabe et al. | Jun 1994 | A |
| 5323772 | Linden et al. | Jun 1994 | A |
| 5325861 | Goulding | Jul 1994 | A |
| 5333606 | Schneider et al. | Aug 1994 | A |
| 5335650 | Shaffer et al. | Aug 1994 | A |
| 5335654 | Rapoport | Aug 1994 | A |
| 5339807 | Carter | Aug 1994 | A |
| 5343857 | Schneider et al. | Sep 1994 | A |
| 5351522 | Lura | Oct 1994 | A |
| 5357946 | Kee et al. | Oct 1994 | A |
| 5368019 | LaTorraca | Nov 1994 | A |
| 5373842 | Olsson et al. | Dec 1994 | A |
| 5383448 | Tkatchouk et al. | Jan 1995 | A |
| 5383449 | Forare et al. | Jan 1995 | A |
| 5385142 | Brady et al. | Jan 1995 | A |
| 5390666 | Kimm et al. | Feb 1995 | A |
| 5395301 | Russek | Mar 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 |
| 5404871 | Goodman et al. | Apr 1995 | A |
| 5407174 | Kumar | Apr 1995 | A |
| 5413110 | Cummings et al. | May 1995 | A |
| 5419314 | Christopher | May 1995 | A |
| 5429123 | Shaffer et al. | Jul 1995 | A |
| 5429124 | Yoshida et al. | Jul 1995 | A |
| 5433193 | Sanders et al. | Jul 1995 | A |
| 5435305 | Rankin, Sr. | Jul 1995 | A |
| 5438980 | Phillips | Aug 1995 | A |
| 5443075 | Holscher | Aug 1995 | A |
| 5458137 | Axe et al. | Oct 1995 | A |
| 5471977 | Olsson et al. | Dec 1995 | A |
| 5474062 | DeVires et al. | Dec 1995 | A |
| 5479920 | Piper et al. | Jan 1996 | A |
| 5487383 | Levinson | Jan 1996 | A |
| 5494028 | DeVries et al. | Feb 1996 | A |
| 5513631 | McWilliams | May 1996 | A |
| 5517983 | Deighan et al. | May 1996 | A |
| 5520071 | Jones | May 1996 | A |
| 5524615 | Power | Jun 1996 | A |
| 5531221 | Power | Jul 1996 | A |
| 5535738 | Estes et al. | Jul 1996 | A |
| 5537999 | Dearman et al. | Jul 1996 | A |
| 5540220 | Gropper et al. | Jul 1996 | A |
| 5542415 | Brody | Aug 1996 | A |
| 5542416 | Chalvignac | Aug 1996 | A |
| 5544674 | Kelly | Aug 1996 | A |
| 5549106 | Gruenke et al. | Aug 1996 | A |
| 5549655 | Erickson | Aug 1996 | A |
| 5551418 | Estes et al. | Sep 1996 | A |
| 5551419 | Froehlich et al. | Sep 1996 | A |
| 5558086 | Smith et al. | Sep 1996 | A |
| 5562918 | Stimpson | Oct 1996 | A |
| 5564416 | Jones | Oct 1996 | A |
| 5582163 | Bonassa | Dec 1996 | A |
| 5590651 | Shaffer et al. | Jan 1997 | A |
| 5596983 | Zander et al. | Jan 1997 | A |
| 5596984 | O'Mahony et al. | Jan 1997 | A |
| 5603315 | Sasso, Jr. | Feb 1997 | A |
| 5603316 | Coufal et al. | Feb 1997 | A |
| 5606968 | Mang | Mar 1997 | A |
| 5630411 | Holscher | May 1997 | A |
| 5632269 | Zdrojkowski | May 1997 | A |
| 5632270 | O'Mahony et al. | May 1997 | A |
| 5642726 | Owens et al. | Jul 1997 | A |
| 5645048 | Brodsky et al. | Jul 1997 | A |
| 5645053 | Remmers et al. | Jul 1997 | A |
| 5647345 | Saul | Jul 1997 | A |
| 5647351 | Weismann et al. | Jul 1997 | A |
| 5651361 | Dearman et al. | Jul 1997 | A |
| 5655519 | Alfery | Aug 1997 | A |
| 5660171 | Kimm et al. | Aug 1997 | A |
| 5664560 | Merrick et al. | Sep 1997 | A |
| 5664562 | Bourdon | Sep 1997 | A |
| 5669379 | Somerson et al. | Sep 1997 | A |
| 5671767 | Kelly | Sep 1997 | A |
| 5672041 | Ringdahl et al. | Sep 1997 | A |
| 5673689 | Power | Oct 1997 | A |
| 5687713 | Bahr et al. | Nov 1997 | A |
| 5692497 | Schnitzer et al. | Dec 1997 | A |
| 5706799 | Imai et al. | Jan 1998 | A |
| 5715812 | Deighan et al. | Feb 1998 | A |
| 5720277 | Olsson et al. | Feb 1998 | A |
| 5724962 | Vidgren et al. | Mar 1998 | A |
| 5727562 | Beck | Mar 1998 | A |
| 5735267 | Tobia | Apr 1998 | A |
| 5738090 | Lachmann et al. | Apr 1998 | A |
| 5740795 | Brydon | Apr 1998 | A |
| 5740796 | Skog | Apr 1998 | A |
| 5740797 | Dickson | Apr 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 |
| 5791339 | Winter | Aug 1998 | A |
| 5794615 | Estes | Aug 1998 | A |
| 5794986 | Gansel et al. | Aug 1998 | A |
| 5803065 | Zdrojkowski et al. | Sep 1998 | A |
| 5803066 | Rapoport et al. | Sep 1998 | A |
| 5806512 | Abramov et al. | Sep 1998 | A |
| 5807245 | Aldestam et al. | Sep 1998 | A |
| 5810000 | Stevens | Sep 1998 | A |
| 5813399 | Isaza et al. | Sep 1998 | A |
| 5813401 | Radcliff et al. | Sep 1998 | A |
| 5814086 | Hirschberg et al. | Sep 1998 | A |
| 5826575 | Lall | Oct 1998 | A |
| 5829441 | Kidd et al. | Nov 1998 | A |
| 5864938 | Gansel et al. | Feb 1999 | A |
| 5865168 | Isaza | Feb 1999 | A |
| 5865173 | Froehlich | Feb 1999 | A |
| 5868133 | DeVries et al. | Feb 1999 | A |
| 5876352 | Weismann | Mar 1999 | A |
| 5878744 | Pfeiffer | Mar 1999 | A |
| 5881717 | Isaza | Mar 1999 | A |
| 5881723 | Wallace et al. | Mar 1999 | A |
| 5881725 | Hoffman et al. | Mar 1999 | A |
| 5884623 | Winter | Mar 1999 | A |
| 5906203 | Klockseth et al. | May 1999 | A |
| 5909731 | O'Mahony et al. | Jun 1999 | A |
| 5911218 | DiMarco | Jun 1999 | A |
| 5915379 | Wallace et al. | Jun 1999 | A |
| 5915380 | Wallace et al. | Jun 1999 | A |
| 5915381 | Nord | 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 |
| 5931162 | Christian | Aug 1999 | A |
| 5934274 | Merrick et al. | Aug 1999 | A |
| 5937853 | Strom | Aug 1999 | A |
| 5944680 | Christopherson | Aug 1999 | A |
| 5970975 | Estes et al. | Oct 1999 | A |
| 5996580 | Swann | Dec 1999 | A |
| 6015388 | Sackner et al. | Jan 2000 | A |
| 6019100 | Alving et al. | Feb 2000 | A |
| 6024089 | Wallace et al. | Feb 2000 | A |
| 6029664 | Zdrojkowski et al. | Feb 2000 | A |
| 6029665 | Berthon-Jones | Feb 2000 | A |
| 6041780 | Richard et al. | Mar 2000 | A |
| 6044841 | Verdun et al. | Apr 2000 | A |
| 6047860 | Sanders | Apr 2000 | A |
| 6066101 | Johnson et al. | May 2000 | A |
| 6068602 | Tham et al. | May 2000 | A |
| 6076519 | Johnson | Jun 2000 | A |
| 6076523 | Jones et al. | Jun 2000 | A |
| 6095140 | Poon et al. | Aug 2000 | A |
| 6109260 | Bathe | 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 |
| 6131571 | Lampotang et al. | Oct 2000 | A |
| 6131572 | Heinonen | Oct 2000 | A |
| 6135105 | Lampotang et al. | Oct 2000 | A |
| 6135106 | Dirks et al. | Oct 2000 | A |
| 6138675 | Berthon-Jones | Oct 2000 | A |
| 6142150 | O'Mahoney et al. | Nov 2000 | A |
| 6148814 | Clemmer et al. | Nov 2000 | A |
| 6152129 | Berthon Jones | Nov 2000 | A |
| 6152133 | Psaros et al. | Nov 2000 | A |
| 6152135 | DeVries et al. | Nov 2000 | A |
| 6155257 | Lurie et al. | Dec 2000 | A |
| 6158432 | Biondi et al. | Dec 2000 | A |
| 6158433 | Ong et al. | Dec 2000 | A |
| 6161539 | Winter | Dec 2000 | A |
| 6192885 | Jalde | Feb 2001 | B1 |
| 6196222 | Heinonen et al. | Mar 2001 | B1 |
| 6213119 | Brydon et al. | Apr 2001 | B1 |
| 6220244 | McLaughlin | Apr 2001 | B1 |
| 6220245 | Takabayashi et al. | Apr 2001 | B1 |
| 6230708 | Radko | May 2001 | B1 |
| 6257234 | Sun | Jul 2001 | B1 |
| 6260549 | Sosiak | Jul 2001 | B1 |
| 6269812 | Wallace et al. | Aug 2001 | B1 |
| 6273444 | Power | Aug 2001 | B1 |
| 6279569 | Berthon Jones | Aug 2001 | B1 |
| 6279574 | Richardson et al. | Aug 2001 | B1 |
| 6283119 | Bourdon | Sep 2001 | B1 |
| 6305373 | Wallace et al. | Oct 2001 | B1 |
| 6305374 | Zdrojkowski et al. | Oct 2001 | B1 |
| 6308703 | Alving et al. | Oct 2001 | B1 |
| 6308706 | Lammers et al. | Oct 2001 | B1 |
| 6318365 | Vogele et al. | Nov 2001 | B1 |
| 6321748 | O'Mahoney | Nov 2001 | B1 |
| 6325785 | Babkes et al. | Dec 2001 | B1 |
| 6343603 | Tuck et al. | Feb 2002 | B1 |
| 6345619 | Finn | Feb 2002 | B1 |
| 6357438 | Hansen | Mar 2002 | B1 |
| 6360740 | Ward et al. | Mar 2002 | B1 |
| 6360745 | Wallace et al. | Mar 2002 | B1 |
| 6369838 | Wallace et al. | Apr 2002 | B1 |
| 6390091 | Banner et al. | May 2002 | B1 |
| 6390988 | Robinson | May 2002 | B1 |
| 6408847 | Nuckols et al. | Jun 2002 | B1 |
| 6412482 | Rowe | Jul 2002 | B1 |
| 6412483 | Jones et al. | Jul 2002 | B1 |
| 6425392 | Sosiak | Jul 2002 | B1 |
| 6439229 | Du et al. | Aug 2002 | B1 |
| 6450163 | Blacker et al. | Sep 2002 | B1 |
| 6450968 | Wallen et al. | Sep 2002 | B1 |
| 6461315 | Gattinoni | Oct 2002 | B1 |
| 6463930 | Biondi et al. | Oct 2002 | B2 |
| 6467477 | Frank et al. | Oct 2002 | B1 |
| 6467478 | Merrick et al. | Oct 2002 | B1 |
| 6467479 | Albert et al. | Oct 2002 | B1 |
| 6484719 | Berthon Jones | Nov 2002 | B1 |
| 6494201 | Welik | Dec 2002 | B1 |
| 6512938 | Claure et al. | Jan 2003 | B2 |
| 6516800 | Bowden | Feb 2003 | B1 |
| 6517497 | Rymut et al. | Feb 2003 | B2 |
| 6523538 | Wikfeldt | Feb 2003 | B1 |
| 6526970 | DeVries et al. | Mar 2003 | B2 |
| 6532956 | Hill | Mar 2003 | B2 |
| 6532957 | Berthon Jones | Mar 2003 | B2 |
| 6532959 | Berthon Jones | Mar 2003 | B1 |
| 6537228 | Lambert | Mar 2003 | B1 |
| 6539938 | Weinstein et al. | Apr 2003 | B2 |
| 6539940 | Zdrojkowski et al. | Apr 2003 | B2 |
| 6546930 | Emerson et al. | Apr 2003 | B1 |
| 6547743 | Brydon | Apr 2003 | B2 |
| 6553991 | Isaza | Apr 2003 | B1 |
| 6553992 | Berthon Jones et al. | Apr 2003 | B1 |
| 6557553 | Borrello | May 2003 | B1 |
| 6564798 | Jalde | May 2003 | B1 |
| 6571795 | Bourdon | Jun 2003 | B2 |
| 6571796 | Banner et al. | Jun 2003 | B2 |
| 6575163 | Berthon Jones | Jun 2003 | B1 |
| 6575164 | Jaffe et al. | Jun 2003 | B1 |
| 6578575 | Jonson | Jun 2003 | B1 |
| 6581599 | Stenzler | Jun 2003 | B1 |
| 6588423 | Sinderby | Jul 2003 | B1 |
| 6595212 | Arnott | Jul 2003 | B1 |
| 6595213 | Bennarsten | Jul 2003 | B2 |
| 6601583 | Pessala et al. | Aug 2003 | B2 |
| 6609517 | Estes et al. | Aug 2003 | B1 |
| 6609518 | Lamb | Aug 2003 | B2 |
| 6622725 | Fisher et al. | Sep 2003 | B1 |
| 6622726 | Du | Sep 2003 | B1 |
| 6626175 | Jafari et al. | Sep 2003 | B2 |
| 6631716 | Robinson et al. | Oct 2003 | B1 |
| 6631717 | Rich et al. | Oct 2003 | B1 |
| 6644310 | Delache et al. | Nov 2003 | B1 |
| 6651652 | Ward | Nov 2003 | B1 |
| 6659101 | Berthon Jones | Dec 2003 | B2 |
| 6659961 | Robinson | Dec 2003 | B2 |
| 6668824 | Isaza et al. | Dec 2003 | B1 |
| 6668829 | Biondi et al. | Dec 2003 | B2 |
| 6671529 | Claure et al. | Dec 2003 | B2 |
| 6675801 | Wallace et al. | Jan 2004 | B2 |
| 6679258 | Strom | Jan 2004 | B1 |
| 6681643 | Heinonen | Jan 2004 | B2 |
| 6688307 | Berthon Jones | Feb 2004 | B2 |
| 6689091 | Bui et al. | Feb 2004 | B2 |
| 6694978 | Bennarsten | Feb 2004 | B1 |
| 6718974 | Moberg | Apr 2004 | B1 |
| 6722360 | Doshi | Apr 2004 | B2 |
| 6725447 | Gilman et al. | Apr 2004 | B1 |
| 6726598 | Jarvis et al. | Apr 2004 | B1 |
| 6739337 | Isaza | May 2004 | B2 |
| 6745771 | Castor et al. | Jun 2004 | B2 |
| 6745773 | Gobel | Jun 2004 | B1 |
| 6752766 | Kowallik et al. | Jun 2004 | B2 |
| 6752772 | Kahn | Jun 2004 | B2 |
| 6755193 | Berthon Jones et al. | Jun 2004 | B2 |
| 6758216 | Berthon Jones et al. | Jul 2004 | B1 |
| 6761167 | Nadjafizadeh et al. | Jul 2004 | B1 |
| 6761168 | Nadjafizadeh et al. | Jul 2004 | B1 |
| 6763829 | Jaffe et al. | Jul 2004 | B2 |
| 6786217 | Stenzler | Sep 2004 | B2 |
| 6796305 | Banner et al. | Sep 2004 | B1 |
| 6805118 | Brooker et al. | Oct 2004 | B2 |
| 6810876 | Berthon Jones | Nov 2004 | B2 |
| 6814074 | Nadjafizadeh et al. | Nov 2004 | B1 |
| 6814075 | Boussignac | Nov 2004 | B2 |
| 6820613 | Wenkebach et al. | Nov 2004 | B2 |
| 6820618 | Banner et al. | Nov 2004 | B2 |
| 6823866 | Jafari et al. | Nov 2004 | B2 |
| 6834647 | Blair et al. | Dec 2004 | B2 |
| 6837241 | Samzelius | Jan 2005 | B2 |
| 6837242 | Younes | Jan 2005 | B2 |
| 6840240 | Berthon Jones et al. | Jan 2005 | B1 |
| 6851427 | Nashed | Feb 2005 | B1 |
| 6860264 | Christopher | Mar 2005 | B2 |
| 6860265 | Emerson | Mar 2005 | B1 |
| 6860858 | Green et al. | Mar 2005 | B2 |
| 6863068 | Jamison et al. | Mar 2005 | B2 |
| 6863656 | Lurie | Mar 2005 | B2 |
| 6866040 | Bourdon | Mar 2005 | B1 |
| 6877511 | DeVries et al. | Apr 2005 | B2 |
| 6910480 | Berthon Jones | Jun 2005 | B1 |
| 6920875 | Hill et al. | Jul 2005 | B1 |
| 6920878 | Sinderby et al. | Jul 2005 | B2 |
| 6938619 | Hickle | Sep 2005 | B1 |
| 6948497 | Zdrojkowski et al. | Sep 2005 | B2 |
| 6960854 | Nadjafizadeh et al. | Nov 2005 | B2 |
| 6976487 | Melker et al. | Dec 2005 | B1 |
| 6988498 | Berthon-Jones et al. | Jan 2006 | B2 |
| 6990980 | Richey, II | Jan 2006 | B2 |
| 6997881 | Green et al. | Feb 2006 | B2 |
| 7000612 | Jafari et al. | Feb 2006 | B2 |
| 7001339 | Lin | Feb 2006 | B2 |
| 7001340 | Lin | Feb 2006 | B2 |
| 7008380 | Rees et al. | Mar 2006 | B1 |
| 7011091 | Hill et al. | Mar 2006 | B2 |
| 7011092 | McCombs et al. | Mar 2006 | B2 |
| 7013892 | Estes et al. | Mar 2006 | B2 |
| 7017574 | Biondi et al. | Mar 2006 | B2 |
| 7036504 | Wallace et al. | May 2006 | B2 |
| 7040321 | Gobel et al. | May 2006 | B2 |
| 7051736 | Banner et al. | May 2006 | B2 |
| 7055522 | Berthon Jones | Jun 2006 | B2 |
| 7066173 | Banner et al. | Jun 2006 | B2 |
| 7066175 | Hamilton et al. | Jun 2006 | B2 |
| 7066176 | Jaffe et al. | Jun 2006 | B2 |
| 7070570 | Sanderson et al. | Jul 2006 | B2 |
| 7077131 | Hansen | Jul 2006 | B2 |
| 7077132 | Berthon-Jones | Jul 2006 | B2 |
| 7080646 | Wiesmann et al. | Jul 2006 | B2 |
| RE39225 | Isaza et al. | Aug 2006 | E |
| 7087027 | Page | Aug 2006 | B2 |
| 7089932 | Dodds | Aug 2006 | B2 |
| 7100607 | Zdrojkowski et al. | Sep 2006 | B2 |
| 7100609 | Berthon Jones et al. | Sep 2006 | B2 |
| 7104962 | Lomask et al. | Sep 2006 | B2 |
| 7117438 | Wallace et al. | Oct 2006 | B2 |
| 7121277 | Ström | Oct 2006 | B2 |
| 7128069 | Farrugia et al. | Oct 2006 | B2 |
| 7137389 | Berthon Jones | Nov 2006 | B2 |
| 7152598 | Morris et al. | Dec 2006 | B2 |
| 7152604 | Hickle et al. | Dec 2006 | B2 |
| 7156095 | Melker et al. | Jan 2007 | B2 |
| 7162296 | Leonhardt et al. | Jan 2007 | B2 |
| 7191780 | Faram | Mar 2007 | B2 |
| 7210478 | Banner et al. | May 2007 | B2 |
| 7211049 | Bradley et al. | May 2007 | B2 |
| 7226427 | Steen | Jun 2007 | B2 |
| 7255103 | Bassin | Aug 2007 | B2 |
| 7267652 | Coyle et al. | Sep 2007 | B2 |
| 7270126 | Wallace et al. | Sep 2007 | B2 |
| 7275540 | Bolam et al. | Oct 2007 | B2 |
| 7276031 | Norman et al. | Oct 2007 | B2 |
| 7311668 | Lurie | Dec 2007 | B2 |
| 7334578 | Biondi et al. | Feb 2008 | B2 |
| 7334581 | Doshi | Feb 2008 | B2 |
| 7347205 | Levi | Mar 2008 | B2 |
| 7363925 | Pagan | Apr 2008 | B2 |
| 7367337 | Berthon Jones et al. | May 2008 | B2 |
| 7369757 | Farbarik | May 2008 | B2 |
| 7370650 | Nadjafizadeh et al. | May 2008 | B2 |
| 7390304 | Chen et al. | Jun 2008 | B2 |
| 7392806 | Yuen et al. | Jul 2008 | B2 |
| 7422015 | Delisle et al. | Sep 2008 | B2 |
| 7425201 | Euliano et al. | Sep 2008 | B2 |
| 7428902 | Du et al. | Sep 2008 | B2 |
| 7445006 | Dhuper et al. | Nov 2008 | B2 |
| 7460959 | Jafari | Dec 2008 | B2 |
| 7464711 | Flodin | Dec 2008 | B2 |
| 7467012 | Park et al. | Dec 2008 | B1 |
| 7472702 | Beck et al. | Jan 2009 | B2 |
| 7484508 | Younes | Feb 2009 | B2 |
| 7487773 | Li | Feb 2009 | B2 |
| 7487774 | Acker | Feb 2009 | B2 |
| 7487775 | Mashak | Feb 2009 | B2 |
| 7509957 | Duquette et al. | Mar 2009 | B2 |
| 7523752 | Montgomery et al. | Apr 2009 | B2 |
| 7530353 | Choncholas et al. | May 2009 | B2 |
| 7547285 | Kline | Jun 2009 | B2 |
| 7549421 | Levi et al. | Jun 2009 | B2 |
| 7552731 | Jorczak et al. | Jun 2009 | B2 |
| 7556038 | Kirby et al. | Jul 2009 | B2 |
| 7559326 | Smith et al. | Jul 2009 | B2 |
| 7572225 | Stahmann et al. | Aug 2009 | B2 |
| 7574246 | Krebs et al. | Aug 2009 | B2 |
| 7584752 | Garber et al. | Sep 2009 | B2 |
| 7588033 | Wondka | Sep 2009 | B2 |
| 7588543 | Euliano et al. | Sep 2009 | B2 |
| 7594508 | Doyle | Sep 2009 | B2 |
| 7610914 | Bolam et al. | Nov 2009 | B2 |
| 7617821 | Hughes | Nov 2009 | B2 |
| 7617825 | Pedemonte | Nov 2009 | B2 |
| 7621270 | Morris et al. | Nov 2009 | B2 |
| 7624736 | Borody | Dec 2009 | B2 |
| 7634998 | Fenley | Dec 2009 | B1 |
| 7644713 | Berthon Jones | Jan 2010 | B2 |
| 7654802 | Crawford, Jr. et al. | Feb 2010 | B2 |
| 7669594 | Downie | Mar 2010 | B2 |
| 7669598 | Rick et al. | Mar 2010 | B2 |
| 7678061 | Lee et al. | Mar 2010 | B2 |
| 7682312 | Lurie | Mar 2010 | B2 |
| 7694677 | Tang | Apr 2010 | B2 |
| 7694682 | Petersen et al. | Apr 2010 | B2 |
| 7717110 | Kane et al. | May 2010 | B2 |
| 7717113 | Andrieux | May 2010 | B2 |
| 7721736 | Urias et al. | 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 |
| 7731663 | Averina et al. | Jun 2010 | B2 |
| 7735486 | Payne | Jun 2010 | B2 |
| 7735492 | Doshi et al. | Jun 2010 | B2 |
| 7775207 | Jaffe et al. | Aug 2010 | B2 |
| 7784461 | Figueiredo et al. | Aug 2010 | B2 |
| 7793656 | Johnson | Sep 2010 | B2 |
| 7798145 | Weismann et al. | Sep 2010 | B2 |
| 7802571 | Tehrani | Sep 2010 | B2 |
| 7809442 | Bolea et al. | Oct 2010 | B2 |
| 7810496 | Estes et al. | Oct 2010 | B2 |
| 7810497 | Pittman et al. | Oct 2010 | B2 |
| 7810498 | Patterson | Oct 2010 | B1 |
| 7814906 | Moretti | Oct 2010 | B2 |
| 7819815 | Younes | Oct 2010 | B2 |
| 7823588 | Hansen | Nov 2010 | B2 |
| 7841341 | Dhuper et al. | Nov 2010 | B2 |
| 7850619 | Gavish et al. | Dec 2010 | B2 |
| 7855716 | McCreary et al. | Dec 2010 | B2 |
| 7865244 | Giftakis et al. | Jan 2011 | B2 |
| 7866318 | Bassin | 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 |
| D638852 | Skidmore et al. | May 2011 | S |
| 7938114 | Matthews et al. | May 2011 | B2 |
| 7963283 | Sinderby | Jun 2011 | B2 |
| 7970475 | Tehrani et al. | Jun 2011 | B2 |
| 7984712 | Soliman et al. | Jul 2011 | B2 |
| 7984714 | Hausmann et al. | Jul 2011 | B2 |
| D643535 | Ross et al. | Aug 2011 | S |
| 7992557 | Nadjafizadeh et al. | Aug 2011 | B2 |
| 7992564 | Doshi et al. | Aug 2011 | B2 |
| 7997271 | Hickle et al. | Aug 2011 | B2 |
| 8001967 | Wallace et al. | Aug 2011 | B2 |
| D645158 | Sanchez et al. | Sep 2011 | S |
| 8021308 | Carlson et al. | Sep 2011 | B2 |
| 8021309 | Zilberg | Sep 2011 | B2 |
| 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 |
| 8231536 | Cho et al. | 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 |
| 8597185 | Pipke | Dec 2013 | B2 |
| 8603006 | Mulqueeny et al. | Dec 2013 | B2 |
| D701601 | Winter | Mar 2014 | S |
| 8792949 | Baker, Jr. | Jul 2014 | B2 |
| 8869795 | Bassin | Oct 2014 | B2 |
| 9808591 | Esmaeil-zadeh-azar | Nov 2017 | B2 |
| 20010004893 | Biondi et al. | Jun 2001 | A1 |
| 20010007255 | Stumpf | Jul 2001 | A1 |
| 20020017301 | Lundin | Feb 2002 | A1 |
| 20020023640 | Nightengale | Feb 2002 | A1 |
| 20020026941 | Biondi et al. | Mar 2002 | A1 |
| 20020042564 | Cooper et al. | Apr 2002 | A1 |
| 20020042565 | Cooper et al. | Apr 2002 | A1 |
| 20020046753 | Lamb | Apr 2002 | A1 |
| 20020072685 | Rymut et al. | Jun 2002 | A1 |
| 20020073993 | Weinstein et al. | Jun 2002 | A1 |
| 20020174866 | Orr et al. | Nov 2002 | A1 |
| 20020185126 | Krebs | Dec 2002 | A1 |
| 20020195105 | Blue et al. | Dec 2002 | A1 |
| 20030010339 | Banner et al. | Jan 2003 | A1 |
| 20030034031 | Lev et al. | Feb 2003 | A1 |
| 20030037786 | Biondi et al. | Feb 2003 | A1 |
| 20030125662 | Bui | Jul 2003 | A1 |
| 20030131848 | Stenzler | Jul 2003 | A1 |
| 20030136402 | Jiang et al. | Jul 2003 | A1 |
| 20030140925 | Sapienza et al. | Jul 2003 | A1 |
| 20030145853 | Muellner | Aug 2003 | A1 |
| 20030154979 | Berthon Jones | Aug 2003 | A1 |
| 20030159695 | Younes | Aug 2003 | A1 |
| 20030172929 | Muellner | Sep 2003 | A1 |
| 20030178024 | Allan et al. | Sep 2003 | A1 |
| 20030192544 | Berthon Jones et al. | Oct 2003 | A1 |
| 20030216660 | Ben-Oren et al. | Nov 2003 | A1 |
| 20030225339 | Orr et al. | Dec 2003 | A1 |
| 20040016431 | Preveyraud | Jan 2004 | A1 |
| 20040103896 | Jafari et al. | Jun 2004 | A1 |
| 20040133123 | Leonhardt et al. | Jul 2004 | A1 |
| 20040149282 | Hickle | Aug 2004 | A1 |
| 20040159323 | Schmidt et al. | Aug 2004 | A1 |
| 20040187864 | Adams | Sep 2004 | A1 |
| 20040194779 | Doshi | Oct 2004 | A1 |
| 20040194780 | Doshi | Oct 2004 | A1 |
| 20040200477 | Bleys et al. | Oct 2004 | A1 |
| 20040206355 | Berthon Jones et al. | Oct 2004 | A1 |
| 20040221847 | Berthon Jones et al. | Nov 2004 | A1 |
| 20040231670 | Bassin | Nov 2004 | A1 |
| 20040244804 | Olsen et al. | Dec 2004 | A1 |
| 20050022809 | Wondka | Feb 2005 | A1 |
| 20050027252 | Boukas | Feb 2005 | A1 |
| 20050039748 | Andrieux | Feb 2005 | A1 |
| 20050061318 | Faram | Mar 2005 | A1 |
| 20050076907 | Stenzler | Apr 2005 | A1 |
| 20050085865 | Tehrani | Apr 2005 | A1 |
| 20050085867 | Tehrani et al. | Apr 2005 | A1 |
| 20050085868 | Tehrani et al. | Apr 2005 | A1 |
| 20050098179 | Burton et al. | May 2005 | A1 |
| 20050103331 | Wedemeyer | May 2005 | A1 |
| 20050109339 | Stahmann et al. | May 2005 | A1 |
| 20050109340 | Tehrani | May 2005 | A1 |
| 20050126565 | Huang | Jun 2005 | A1 |
| 20050133028 | Pagan | Jun 2005 | A1 |
| 20050139212 | Bourdon | Jun 2005 | A1 |
| 20050199237 | Lurie | Sep 2005 | A1 |
| 20050217671 | Fisher et al. | Oct 2005 | A1 |
| 20050241639 | Zilberg | Nov 2005 | A1 |
| 20050263152 | Fong | Dec 2005 | A1 |
| 20050279358 | Richey, II | Dec 2005 | A1 |
| 20050284469 | Tobia et al. | Dec 2005 | A1 |
| 20060011195 | Zarychta | Jan 2006 | A1 |
| 20060021618 | Berthon-Jones et al. | Feb 2006 | A1 |
| 20060021620 | Calluaud et al. | Feb 2006 | A1 |
| 20060032497 | Doshi | Feb 2006 | A1 |
| 20060094972 | Drew | May 2006 | A1 |
| 20060102180 | Berthon Jones | May 2006 | A1 |
| 20060122662 | Tehrani et al. | Jun 2006 | A1 |
| 20060142815 | Tehrani et al. | Jun 2006 | A1 |
| 20060162727 | Biondi et al. | Jul 2006 | A1 |
| 20060178245 | Schiller et al. | Aug 2006 | A1 |
| 20060196507 | Bradley | Sep 2006 | A1 |
| 20060196508 | Chalvignac | Sep 2006 | A1 |
| 20060201507 | Breen | Sep 2006 | A1 |
| 20060241708 | Boute | Oct 2006 | A1 |
| 20060249148 | Younes | Nov 2006 | A1 |
| 20060249155 | Gambone | Nov 2006 | A1 |
| 20060272642 | Chalvignac | Dec 2006 | A1 |
| 20060276718 | Madaus et al. | Dec 2006 | A1 |
| 20060278221 | Schermeier et al. | Dec 2006 | A1 |
| 20060278224 | Shaffer et al. | Dec 2006 | A1 |
| 20060283450 | Shissler et al. | Dec 2006 | A1 |
| 20060283451 | Albertelli | Dec 2006 | A1 |
| 20070000494 | Banner et al. | Jan 2007 | A1 |
| 20070017515 | Wallace et al. | Jan 2007 | A1 |
| 20070017518 | Farrugia et al. | Jan 2007 | A1 |
| 20070028921 | Banner et al. | Feb 2007 | A1 |
| 20070044796 | Zdrojkowski et al. | Mar 2007 | A1 |
| 20070062529 | Choncholas et al. | Mar 2007 | A1 |
| 20070062532 | Choncholas | Mar 2007 | A1 |
| 20070062533 | Choncholas et al. | Mar 2007 | A1 |
| 20070068528 | Bohm et al. | Mar 2007 | A1 |
| 20070077200 | Baker | Apr 2007 | A1 |
| 20070113843 | Hughes | May 2007 | A1 |
| 20070123792 | Kline | May 2007 | A1 |
| 20070129646 | Heinonen et al. | Jun 2007 | A1 |
| 20070144523 | Bolam et al. | Jun 2007 | A1 |
| 20070151563 | Ozaki et al. | Jul 2007 | A1 |
| 20070157931 | Parker et al. | Jul 2007 | A1 |
| 20070163590 | Bassin | Jul 2007 | A1 |
| 20070181122 | Mulier | Aug 2007 | A1 |
| 20070186928 | Be'Eri | Aug 2007 | A1 |
| 20070191787 | Lim et al. | Aug 2007 | A1 |
| 20070208267 | Schmid et al. | Sep 2007 | A1 |
| 20070221222 | Lurie | Sep 2007 | A1 |
| 20070225623 | Freeman | Sep 2007 | A1 |
| 20070227537 | Bemister et al. | Oct 2007 | A1 |
| 20070227538 | Scholler et al. | Oct 2007 | A1 |
| 20070227539 | Schwaibold et al. | Oct 2007 | A1 |
| 20070267015 | Thoemmes et al. | Nov 2007 | A1 |
| 20070272241 | Sanborn et al. | Nov 2007 | A1 |
| 20070272243 | Sherman et al. | Nov 2007 | A1 |
| 20070277825 | Bordewick et al. | Dec 2007 | A1 |
| 20070284361 | Nadjafizadeh et al. | Dec 2007 | A1 |
| 20080000471 | Bolam et al. | Jan 2008 | A1 |
| 20080000475 | Hill | Jan 2008 | A1 |
| 20080000478 | Matthiessen et al. | Jan 2008 | A1 |
| 20080011294 | Heesch et al. | Jan 2008 | A1 |
| 20080017198 | Ivri | Jan 2008 | A1 |
| 20080029096 | Kollmeyer et al. | Feb 2008 | A1 |
| 20080033304 | Dalal et al. | Feb 2008 | A1 |
| 20080035146 | Crabb | Feb 2008 | A1 |
| 20080041382 | Matthews et al. | Feb 2008 | A1 |
| 20080041383 | Matthews et al. | Feb 2008 | A1 |
| 20080053441 | Gottlib et al. | Mar 2008 | A1 |
| 20080060656 | Isaza | Mar 2008 | A1 |
| 20080072896 | Setzer et al. | Mar 2008 | A1 |
| 20080072902 | Setzer et al. | Mar 2008 | A1 |
| 20080078390 | Milne et al. | Apr 2008 | A1 |
| 20080083644 | Janbakhsh et al. | Apr 2008 | A1 |
| 20080091117 | Choncholas et al. | Apr 2008 | A1 |
| 20080092894 | Nicolazzi et al. | Apr 2008 | A1 |
| 20080097234 | Nicolazzi et al. | Apr 2008 | A1 |
| 20080110462 | Chekal et al. | May 2008 | A1 |
| 20080115786 | Sinderby et al. | May 2008 | A1 |
| 20080125828 | Ignagni et al. | May 2008 | A1 |
| 20080135044 | Freitag et al. | Jun 2008 | A1 |
| 20080139956 | Diong | Jun 2008 | A1 |
| 20080142019 | Lewis et al. | Jun 2008 | A1 |
| 20080156330 | Smith et al. | Jul 2008 | A1 |
| 20080163872 | Negele et al. | Jul 2008 | A1 |
| 20080168990 | Cooke et al. | Jul 2008 | A1 |
| 20080178880 | Christopher et al. | Jul 2008 | A1 |
| 20080178882 | Christopher et al. | Jul 2008 | A1 |
| 20080183239 | Tehrani et al. | Jul 2008 | A1 |
| 20080183240 | Tehrani et al. | Jul 2008 | A1 |
| 20080188903 | Tehrani et al. | Aug 2008 | A1 |
| 20080202525 | Mitton et al. | Aug 2008 | A1 |
| 20080208281 | Tehrani et al. | Aug 2008 | A1 |
| 20080216833 | Pujol et al. | Sep 2008 | A1 |
| 20080251078 | Buckley et al. | Oct 2008 | A1 |
| 20080257337 | Denyer et al. | Oct 2008 | A1 |
| 20080275513 | Lattner et al. | Nov 2008 | A1 |
| 20080276940 | Fuhrman et al. | Nov 2008 | A1 |
| 20080281219 | Glickman et al. | Nov 2008 | A1 |
| 20080283060 | Bassin | Nov 2008 | A1 |
| 20080283061 | Tiedje | Nov 2008 | A1 |
| 20080294060 | Haro et al. | Nov 2008 | A1 |
| 20080295837 | McCormick et al. | Dec 2008 | A1 |
| 20080295839 | Habashi | Dec 2008 | A1 |
| 20080295840 | Glaw | Dec 2008 | A1 |
| 20090007914 | Bateman | Jan 2009 | A1 |
| 20090013999 | Bassin | Jan 2009 | A1 |
| 20090038617 | Berthon-Jones et al. | Feb 2009 | A1 |
| 20090056709 | Worsoff | Mar 2009 | A1 |
| 20090095297 | Hallett | Apr 2009 | A1 |
| 20090114223 | Bonassa | May 2009 | A1 |
| 20090120439 | Goebel | May 2009 | A1 |
| 20090137919 | Bar-Lavie et al. | May 2009 | A1 |
| 20090139522 | Thomson et al. | Jun 2009 | A1 |
| 20090165795 | Nadjafizadeh et al. | Jul 2009 | A1 |
| 20090171176 | Andersohn | Jul 2009 | A1 |
| 20090205660 | Thomson et al. | Aug 2009 | A1 |
| 20090205661 | Stephenson et al. | Aug 2009 | A1 |
| 20090205663 | Vandine et al. | Aug 2009 | A1 |
| 20090241952 | Nicolazzi et al. | Oct 2009 | A1 |
| 20090241953 | Vandine 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 |
| 20090266360 | Acker et al. | Oct 2009 | A1 |
| 20090277448 | Ahlmén et al. | Nov 2009 | A1 |
| 20090301486 | Masic | Dec 2009 | A1 |
| 20090301487 | Masic | Dec 2009 | A1 |
| 20090301488 | Sun | Dec 2009 | A1 |
| 20090301490 | Masic | Dec 2009 | A1 |
| 20090301491 | Masic et al. | Dec 2009 | A1 |
| 20090308393 | Luceros | Dec 2009 | 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 |
| 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 |
| 20100076322 | Shrivastav et al. | Mar 2010 | A1 |
| 20100076323 | Shrivastav et al. | Mar 2010 | A1 |
| 20100078017 | Andrieux 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 |
| 20100089396 | Richard et al. | Apr 2010 | A1 |
| 20100108066 | Martin et al. | May 2010 | A1 |
| 20100116270 | Edwards et al. | May 2010 | A1 |
| 20100125227 | Bird | May 2010 | A1 |
| 20100139660 | Adahan | Jun 2010 | A1 |
| 20100145211 | Yamamori | Jun 2010 | A1 |
| 20100147303 | Jafari et al. | Jun 2010 | A1 |
| 20100186744 | Andrieux | Jul 2010 | A1 |
| 20100218765 | Jafari et al. | Sep 2010 | A1 |
| 20100218766 | Milne | Sep 2010 | A1 |
| 20100218767 | Jafari et al. | Sep 2010 | A1 |
| 20100229863 | Enk | Sep 2010 | A1 |
| 20100236551 | Enk | Sep 2010 | A1 |
| 20100236555 | Jafari et al. | Sep 2010 | A1 |
| 20100242961 | Mougel et al. | Sep 2010 | A1 |
| 20100249549 | Baker, Jr. et al. | Sep 2010 | A1 |
| 20100249584 | Albertelli | Sep 2010 | A1 |
| 20100252046 | Dahlstrë{umlaut over ( )}m et al. | Oct 2010 | A1 |
| 20100258124 | Madaus et al. | Oct 2010 | A1 |
| 20100263669 | Bowsher | Oct 2010 | A1 |
| 20100275921 | Schindhelm et al. | Nov 2010 | A1 |
| 20100282259 | Figueiredo et al. | Nov 2010 | A1 |
| 20100288283 | Campbell et al. | Nov 2010 | A1 |
| 20100300446 | Nicolazzi et al. | Dec 2010 | A1 |
| 20110011400 | Gentner et al. | Jan 2011 | A1 |
| 20110011403 | Hannah 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 |
| 20110030686 | Wilkinson et al. | Feb 2011 | A1 |
| 20110041849 | Chen et al. | Feb 2011 | A1 |
| 20110041850 | Vandine et al. | Feb 2011 | A1 |
| 20110073112 | DiBlasi et al. | Mar 2011 | A1 |
| 20110092841 | Bassin | Apr 2011 | A1 |
| 20110100365 | Wedler et al. | May 2011 | A1 |
| 20110112424 | Kesselman et al. | May 2011 | A1 |
| 20110112425 | Muhlsteff et al. | May 2011 | A1 |
| 20110124982 | Pipke | May 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 |
| 20110132363 | Chalvignac | 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 |
| 20110205361 | Guillot et al. | Aug 2011 | A1 |
| 20110208081 | Smith 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 |
| 20110226248 | Duff 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 |
| 20110271960 | Milne et al. | Nov 2011 | A1 |
| 20110273299 | Milne et al. | Nov 2011 | A1 |
| 20110301481 | Heyer 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 |
| 20120029317 | Doyle et al. | Feb 2012 | A1 |
| 20120030611 | Skidmore | 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 |
| 20120133519 | Milne et al. | May 2012 | A1 |
| 20120136222 | Doyle et al. | May 2012 | A1 |
| 20120137249 | Milne et al. | May 2012 | A1 |
| 20120137250 | Milne et al. | May 2012 | A1 |
| 20120152249 | Eger et al. | Jun 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 et al. | 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 |
| 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 |
| 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 |
| 20130284172 | Doyle et al. | Oct 2013 | A1 |
| 20130284173 | Masic et al. | Oct 2013 | A1 |
| 20130284177 | Li 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 |
| 20140000606 | Doyle et al. | Jan 2014 | A1 |
| 20140012150 | Milne et al. | Jan 2014 | A1 |
| 20140034054 | Angelico et al. | Feb 2014 | A1 |
| 20140034056 | Leone et al. | Feb 2014 | A1 |
| 20140041656 | Jourdain et al. | Feb 2014 | A1 |
| 20140048071 | Milne et al. | Feb 2014 | A1 |
| 20140048072 | Angelico et al. | Feb 2014 | A1 |
| 20140053840 | Liu | Feb 2014 | A1 |
| 20140066725 | Mulqueeny et al. | Mar 2014 | A1 |
| 20140121553 | Milne et al. | May 2014 | A1 |
| 20140123979 | Doyle et al. | May 2014 | A1 |
| 20140130798 | Milne 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 |
| 20140290657 | Vandine et al. | Oct 2014 | A1 |
| 20140345616 | Masic | Nov 2014 | A1 |
| 20140373845 | Dong | Dec 2014 | A1 |
| 20150034082 | Kimm et al. | Feb 2015 | A1 |
| 20150045687 | Nakai et al. | Feb 2015 | A1 |
| Number | Date | Country |
|---|---|---|
| 521515 | Jan 1993 | EP |
| 1005829 | Jun 2000 | EP |
| 1005830 | Jun 2000 | EP |
| 996358 | Jan 2002 | EP |
| 1277435 | Jan 2003 | EP |
| WO 2008008659 | Jan 2008 | WO |
| WO 2008021222 | Feb 2008 | WO |
| WO 2008113752 | Sep 2008 | WO |
| WO 2009060330 | May 2009 | WO |
| Entry |
|---|
| 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. 1998, 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. |
| Boitano, Louis J., “An Evaluation of Home Volume Ventilators That Support OpenCircuit Mouthpiece Ventilation”, Respiratory Care, Nov. 2005, vol. 50, No. 11, pp. 1457-1461. |
| Chan, Steven et al., “A Sequential Probability Test for RAIM”, Abstract, Proceedings of the 17th International Technical Meeting of The Satellite Division of the Institute of Navigation, (ION GNSS 2004), Long Beach, CA, Sep. 2004, 2 pgs. |
| Heinrich, Rene et al., “Real-Time Computation of a Patient's Respiratory Effort During Ventilation”, Journal of Clinical Monitoring and Computing (2006), 20: 193-200. |
| Lai, Tze Leung, “Sequential Analysis: Some Classical Problems and New Challenges”, Statistica Sinica, 11(2001), pp. 303-408. |
| Malladi, D.P. et al., “A generalized Shiryayev sequential probability ratio test for change detection and isolation”, Dept. of Mech. & Aerosp. Eng., California Univ., Los Angeles, CA, USA, Automatic Control, IEEE Transactions, Abstract, Aug. 1999, 1 page. |
| Speyer, J. L. et al., “Shiryayev sequential probability ratio test for redundancy management”, Abstract, Journal of Guidance, Control, and Dynamics, vol. 7, No. 5 (1984), 1 page. |
| Number | Date | Country | |
|---|---|---|---|
| 20180036500 A1 | Feb 2018 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14460615 | Aug 2014 | US |
| Child | 15713951 | US |
