Patent Application
20240091473
A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
The present invention relates to facilitating the movement of secretions produced in the throat and lung areas generally in the direction towards a person's throat and mouth areas using a mechanical ventilator.
Secretions in the human airways can impair perfusion, prevent gas humidification via membranes and obstruct normal air flow in breathing. The secretion of mucus can thicken on the walls of the small airways and develop into more serious health problems for sick patients.
Often patients with respiratory insufficiency suffer from respiratory infections, are chronically hyper secretive or have arrived at the condition of respiratory insufficiency through a muscular weakness that also prevents productive coughing to mobilize and eliminate mucus buildup.
These patients who benefit from the assistance of a mechanical ventilator may consequently suffer from worsening mucus buildup because the positive applied pressure at the mouth or tracheal interface tends to push excretions in the caudal (wrong) direction for airway clearance.
It is further realized that the application of mechanical ventilation through an artificial airway often blocks the ability of the patient to extract or swallow elevated airway secretions.
Currently it is common for caregivers to undertake specific, adjunct therapies for mechanically ventilated patients to induce the movement of secretions toward the upper airway such as hyperinflation, PEEP-ZEEP maneuvers, rib cage compression or by employing Mechanical Insufflation Exsufflation (MI-E) devices.
These devices and exercises produce a high expiratory flow rate that shears the mucus away from the cell walls and facilitates movement away from the lungs toward the main bronchus.
However, these techniques, are often invasive and require assistance from trained professionals to implement, which can by a drain on human capital or make homecare solutions difficult.
The present disclosure and embodiments provided below seek to provide a solution that reduces human capital while utilizing current mechanical ventilator equipment to provide a mucus clearing system. These solutions as well as other advantages will become apparent to those skilled in the art from the written description provided.
In one embodiment A method of using a ventilator to aid in clearing mucus comprises the steps of: 1) inputting into the ventilator a target flow bias ratio, wherein the target flow bias ratio is in the direction of expiration; 2) measuring a current flow bias ratio of the ventilator, 3) comparing the target flow bias ratio to the measured current flow bias ratio; and 4) modifying at least one of the operational parameters of the ventilator: a) rise time, b) fall time or c) inspiratory time, when the measured current flow bias ratio is not within a predetermined range of the target flow bias ratio.
The method above can further include the step of measuring the fall time of the ventilator and determining if the fall time of the ventilator has reached a pre-determined minimum.
The method above can further include the step of generating a new fall time if the measured fall time has not reached the pre-determined minimum.
The method above can further include the step of generating a new rise time, a new fall time and a new inspiratory time if the measured fall time has reached the pre-determined minimum.
The methods above wherein the ventilator is configured to maintain a prescribed pressure treatment level.
A variation to the method of using the ventilator above, wherein the modification step is configured to incrementally increase the measured flow bias ratio until it achieves the desired target flow bias ratio over a period of breaths. The period of breaths is at least 5 breaths, at least 10 breaths, at least 15 breaths, at least 20 breaths, or at least 25 breaths.
The fall time in the above methods can be reduced so as to increase the measured flow bias ratio. Alternatively, the fall time can be increased so as to reduce the measured flow bias ratio.
In yet another embodiment a mucus clearing assistance system comprised of: a ventilator system configured to provide positive air pressure to a user; one or more sensors configured to detect flow rate associated with the ventilator; and a controller configured to change one or more output parameters associated with the ventilator, wherein the controller has programmable logic or memory and a processing unit configured to perform the following steps: 1) receive a target flow bias ratio input, 2) receive from the one or more sensors, a measured flow rate, 3) determine from the measured flow rate a flow bias ratio, 4) compare the measured flow bias ratio to the target bias ratio, 5) determine if the measured flow bias ratio needs to be increased or decreased, and 6) modifying at least one of: a fall time parameter, a rise time parameter, and an inspiratory time parameter based on the determination to increase or decrease the measured flow bias ratio.
The above mucus clearing assistance system can be designed wherein the fall time and rise time parameters are based on the rate at which each is pressurized or depressurized. The controller can also be configured to modify the pressurization and de-pressurization rates of the ventilator.
The above mucus clearing assistance system can be designed wherein the controller is further configured determine if the fall time of the ventilator has reached a pre-determined minimum.
The above mucus clearing assistance system can be designed wherein the controller can generate a new fall time if the measured fall time has not reached the pre-determined minimum.
The above mucus clearing assistance system can be designed wherein the controller is further configured to perform the step of generating a new rise time, a new fall time and a new inspiratory time if the measured fall time has reached the pre-determined minimum.
These and other embodiments will become apparent to those skilled in the art upon reviewing the rest of the application.
The foregoing and other objects, features, and advantages of the invention will be apparent from the following description of particular embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
Some definitions that will be helpful for this application including the following:
Inspiratory flow refers to the flow of air entering into and flowing towards the lungs. Expiratory flow refers to the flow of air exiting the lungs and flowing towards the glottis.
Rise Time is the rate at which the pressure ramps up to the prescribed or determined pressure level. The pressure generally rises during inspiration. The rise time of pressure can affect the flow rate and in particular the inspiratory flow rate and in more particular the peak inspiratory flow.
Fall Time is the rate at which the pressure ramps down to a determined pressure level. The pressure generally decreases during expiration. The fall time of pressure can affect the flow rate and in particular the expiratory flow rate and in more particular the peak expiratory flow.
Inspiratory Time is the length of time during which the ventilator delivers the inspiratory pressure.
PEEP is positive end-expiratory pressure.
ZEEP is zero end-expiratory pressure.
Hyperinflation of the lungs refers to overfilling of the lungs.
Prescribed Pressure or Pressure Dosage is the amount of pressure that the ventilator ramps up to during use of the ventilator and is usually prescribed by a medical provider. Units of pressure are usually in the form of cm H2O or centimeters of water column. Prescribed pressures generally range from 5-25 cm H2O, and generally do not exceed 30 cm H2O.
Flow Bias refers to the difference between the peak expiratory flow (PEF) and the peak inspiratory flow (PIF) when both flows have been assigned the same directional sign. E.g. If PIF=30 L/min and PEF=−35 L/min then the Flow Bias is 5 L/min.
Flow Bias Ratio refers to the absolute value of the ratio of PEF/PIF.
Target Flow Bias refers to a prescribed difference or ratio of PEF to PIF to encourage airway clearance.
Measured Flow Bias refers to the measured or observed Flow Bias.
Measured Flow Bias Ratio refers to the measured or observed Flow Bias Ratio.
The term significant used throughout this application, whether significantly reduce, significantly improved, significantly worse, or other variation is meant to convey a statistical or mathematical deviation away from a mean or expected mean. This statistical deviation generally means at least one standard deviation or more, whereas, something less than a standard deviation would NOT be considered significant. Using standard deviation is not always robust, therefore, other forms of deviation could be used such as median absolute deviation. In summary, those skilled in the art of statistics would appreciate when a value has a mathematical or statistical variation that is ‘significant.’
It should be understood that the volume of air inhaled or inspired by a user/patient, generally, and should be equal the volume of air exhaled or expired by a user/patient. If not, the user/patient will have problems. Thus, when user/patients are on ventilator machines, they are designed to maintain an equal volume of air going in and coming out of the lungs.
It is well known that in second order pneumatic systems (a second order pneumatic system is a system in which the dynamics within the system are determined by the pressure, flow and the first derivative of pressure and flow only), the peak flow is determined by the rate of change in the driving pressure. The rate of change in driving pressure is programmed in mechanical ventilator settings by the “Rise Time” and the “Fall Rate” settings. The “Rise Time” affects the peak inspiratory flow because it determines the rate of pressurization at the start of inspiration. The “Fall Time” affects the peak expiratory flow because it determines the rate of depressurization during the start of expiration.
Using an analogy of a leaf blower, the greater flow rate from a more powerful leaf blower is more likely to lift fallen leaves from the ground to gather them for disposal. In this invention, the higher peak expiratory flows induced by fast depressurization of the airways is more likely to lift secretions from the airway walls to gather them near the glottis where they can be removed.
In mechanical ventilation therapy, it is often the case that during assisted inspiration, the leaf blower is pointed in the wrong direction when air is forced into the lungs and it becomes harder for the patient to manage the upward movement of secretions through natural means or through coughing. Thus, from this analogy, it is understood that by controlling or changing the “Rise Time” and “Fall Time” the overall affect of pointing the leaf blower in the correct direction can occur, which is determined by the Target Bias Flow Ratio or Difference.
As noted in the background, previous manual techniques, such as expiratory rib cage compression (ERCC) or monitored techniques, such as hyperinflation, which sometimes include temporarily setting the peak inspiratory pressure to 40 cm H2O, are only designed to be used under monitored situations. This is because each of these techniques require additional tools that medical professionals need to implement, and/or require medical professional monitoring, because the techniques are extreme in nature and are not meant to be utilized constantly. In contrast, the methods and systems discussed herein help to eliminate some of the additional medical professional monitoring and/or implementation, because they can be implemented within the prescribed pressure limits a user/patient is meant to be on over longer periods of time. For example, hyperinflation, which uses pressures of 40 cm H2O, is well outside the normal prescribed range of 5-25 cm H2O for consistent ventilator use. Thus, by automatically modifying the Rise Time, Fall Time and Inspiratory Time parameters, without changing the prescribed pressure the methods and systems described herein can achieve the desired Flow Bias difference or ratio over longer periods of time and avoid additional medical professional time or techniques implemented by medical professionals. In some cases, the consistency of the methods and systems described herein become more effective for clearing mucus from a user/patient, less costly, require less medical professional labor intensive, and can be adapted to utilize existing ventilators in the market.
Referring to flow chart 400A in
These above measurements can be used to determine the PEF and PIF, which can then be used to determine the ratio of PEF/PIF or difference of PEF-PIF. Once the measured Flow Bias is determined, then the next step is to determine if it is within a pre-determined range of the Target Flow Bias. This pre-determined range could be an actual number or it could be determined whether it is statistically insignificant or not based on the Target Flow Bias number entered. For example, if the Target Flow Bias ratio is 1.1 and the measured Flow Bias ratio is 1.0998, this is likely to be within the pre-determined range and thus would require no modification of the current operating parameters of the ventilator as shown through the decision step. Thus, continued measuring would occur until the difference between Target and Measured Flow Bias is outside of the pre-determined range.
When it is determined that the Measured is outside of the pre-determined range, depending on whether that ratio or difference is higher or lower than the target then the next step would be to modify at least one of the following parameters: 1) Rise Time, 2) Fall Time, or 3) Inspiratory Time. In some instances, it may be necessary to adjust more than one of the above parameters. Once the parameter(s) are adjusted the next step is to allow one or more cycles to pass and begin measuring the Flow Bias with the updated parameters. These steps are repeated until the optimal parameters are achieved. It should be noted that a user's/patient's breathing can change over the course of a day or night, as different stages of sleep or awakeness can alter the breathing patterns. Thus, the parameters can constantly and automatically be updating throughout the day based on the user's/patient's biocycle.
Referring to flow chart 400B in
To further illustrate the effects of the above system and methods
For example, in
In another example, in
In yet another example, in
In yet one more example, in
As noted above, by focusing on where the Measured Flow Bias is initially with respect to the Target Flow Bias, the methods and systems described herein can adjust one or more ventilator operating parameters within the prescribed pressure, to achieve operating near the Targeted Flow Bias ratio or difference. When the Flow Bias ratio or difference is set appropriately, this can help move mucus out of the lungs and trachea regions. These methods and systems can be implemented to automatically adjust the operating parameters of the ventilator, when necessary, thus allowing a constant and consistent Flow Bias ratio to be applied to the user, which consistently moves mucus out of the lungs and trachea regions.
While the principles of the invention have been described herein, it is to be understood by those skilled in the art that this description is made only by way of example and not as a limitation as to the scope of the invention. Other embodiments are contemplated within the scope of the present invention in addition to the exemplary embodiments shown and described herein. Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present invention.
| Number | Date | Country | |
|---|---|---|---|
| 63376012 | Sep 2022 | US |
