The diagnosis of asthma (reactive airways disease) requires evidence that the airways will narrow in response to a bronchial provocation exposure to a response eliciting agent. These agents may include for example methacholine, mannitol, cold dry air, or exercise. Bronchial provocation is most frequently performed using an aerosolized liquid methacholine chloride formulation, such as the bronchoconstrictor agent Provocholine (Methapharm Inc., Ontario, Canada). Initially, methacholine chloride is typically provided to health care professionals in powder form, and it is later reconstituted into a liquid dilution (using for example sodium chloride) when it is ready for use. During a methacholine challenge test, the diluted methacholine formulation is inhaled by the subject at increasing concentrations. Patients with asthma demonstrate a particular sensitivity that leads to bronchoconstriction as compared to healthy patients. This difference in response is the basis for the inhalation diagnostic challenge.
There are however shelf life problems with this approach. Once the methacholine powder is mixed with the liquid excipient, it must be used in a very short period (ranging in certain cases from a same day to a two week shelf life). In addition, it needs to be prepared by a pharmacist, which limits where it can be used. An additional problem with aerosolized solutions is the amount of droplets that are discharged into the room that could cause bronchoconstriction in people who should not be exposed to the drug. These include testing technicians, technologists, nurses, physicians as well as other patients in the laboratory for testing. In many cases, testing requires a special exposure chamber with filtered air and a droplet containment component. Additionally, aerosol methods require periodic precision calibration of the aerosol delivery device, which is a significant and elaborate procedure. More than 20 million Americans suffer from asthma and require a correct diagnosis through performance of a bronchial provocation test. Since testing can only be performed at a small number of institutions with proper testing resources and facilities, and private practice physicians are rarely are able to perform this test because of the limitations identified, a need for a better system would benefit the general public.
Another problem associated with approaches for bronchial provocation that require deep inspiration is that deep inspiration can promote both bronchial constriction or bronchial dilatation. Therefore, when performing bronchial provocation testing with methods that use a deep inspiration method to total lung capacity, a lower sensitivity to the response eliciting agent may be exhibited when compared to alternative methods using tidal breathing.
Although dry powder agents such as mannitol may be beneficial to circumvent certain issues mentioned above related to liquid forms (e.g. shelf life, preparation, and test facility limitations) in that there are no exhaled particles to contaminate the air in the laboratory facility, current dry powder inhalation approaches are nonetheless problematic because they typically require deep inspirations. Thus, there is a need in the art for a device and method to deliver dosimeter type challenges in a dry powder form while limiting the range of inspiration during the dose delivery.
In one embodiment, a dry powder delivery device includes a mouthpiece including a proximal and distal opening with a first passageway extending therebetween; a spin chamber including a port and an ejection door, wherein the spin chamber is connected to the first air passageway; a housing including a second passageway, wherein the second passageway is connected to the first passageway and further comprises an airflow sensor; a controller operably connected to the airflow sensor; and a cartridge including a plurality of dry powder receptacles that are configured to align with the port as the cartridge moves relative to the housing. In one embodiment, the second passageway includes an adjustable limiting mechanism configured to limit inhaled volume through the second passageway. In one embodiment, the adjustable limiting mechanism is configured to limit inhaled volume through the second passageway to a level between 0.1 and 3.0 liters of air. In one embodiment, the adjustable limiting mechanism is configured to limit flow through the second passageway to a level between 30 and 120 liters of air per minute. In one embodiment, the adjustable limiting mechanism is configured to limit flow through the second passageway to a level between 60 and 90 liters of air per minute. In one embodiment, the adjustable limiting mechanism is controlled by a motor operably connected to the controller. In one embodiment, the adjustable limiting mechanism is a valve. In one embodiment, the cartridge is configured to move through the housing in a substantially linear direction. In one embodiment, the cartridge is configured to move through the housing in a substantially radial direction. In one embodiment, the cartridge is moved through the housing by a motor operably connected to the controller. In one embodiment, the cartridge is substantially rectangular. In one embodiment, the cartridge is substantially circular. In one embodiment, the sensor is a pressure transducer. In one embodiment, the mouthpiece is a detachable mouthpiece connected to the housing. In one embodiment, a lattice structure is disposed across at least one of the distal opening and the spin chamber. In one embodiment, a first and second air inlet are connected to the spin chamber and positioned to facilitate vortical airflow when a negative pressure is applied to the mouthpiece. In one embodiment, the housing includes a performance indicator including a plurality of light emitting elements. In one embodiment, the plurality of light emitting elements includes a first and second light emitting elements, each having different colors. In one embodiment, the ejection door is actuated by a motor operably connected to the controller. In one embodiment, the dry powder delivery device further includes a piercing element configured to advance at least partially into the spin chamber. In one embodiment, the dry powder delivery device further includes an imaging system including a first camera trained on the spin chamber and operably connected to the controller. In one embodiment, the imaging system includes a second camera trained on the cartridge and operably connected to the controller. In one embodiment, the second pathway includes a one-way elastomeric valve configured to favor proximally directed inspiratory airflow towards the mouthpiece.
In one embodiment, a method for performing an inhalation diagnostic challenge includes inhaling on a mouthpiece of a device; generating a vortical airflow within a spin chamber of the device to spin a first capsule, the first capsule containing dry powder and disposed within the spin chamber, the dry powder containing a first amount of methacholine; releasing at least a first portion of the dry powder from the first capsule; and inhaling an aerosolized form of the first portion of the dry powder released from the capsule. In one embodiment, the method includes advancing the cartridge in a linear direction through the device. In one embodiment, the method includes advancing the cartridge in a radial direction through the device. In one embodiment, the method includes adjusting an airflow through the device by adjusting a volume limiting mechanism. In one embodiment, the method includes ejecting the capsule from the spin chamber.
In one embodiment, the method includes performing an inhalation diagnostic challenge. The method includes the steps of advancing a cartridge comprising a plurality of dry powder capsules through a device housing to deposit a first dry powder capsule into a spin chamber, inhaling on a mouthpiece of the device to generate a vortical airflow within the spin chamber to spin the first capsule, the first capsule containing dry powder containing a first amount of methacholine, releasing at least a first portion of the dry powder from the first capsule, and inhaling an aerosolized form of the first portion of the dry powder released from the capsule. In one embodiment, the second amount of methacholine is greater than the first amount of methacholine. In one embodiment, the second amount of methacholine is substantially two times greater than the first amount of methacholine. In one embodiment, the second amount of methacholine is substantially four times greater than the first amount of methacholine.
In one embodiment, a method for performing an inhalation diagnostic challenge includes advancing a cartridge comprising a plurality of dry powder receptacles through a device housing to deposit a first amount of dry powder into a spin chamber; inhaling on a mouthpiece of the device to generate a vortical airflow within the spin chamber, the first amount of dry powder containing a first amount of methacholine; and inhaling an aerosolized form of the first amount of dry powder. In one embodiment, the method includes advancing the cartridge through the device to deposit a second amount dry powder into the spin chamber; inhaling on the mouthpiece of the device to generate a vortical airflow within the spin chamber, the second amount of dry powder containing a second amount of methacholine different from the first amount of methacholine; and inhaling an aerosolized form of the second amount of dry powder. In one embodiment, the second amount of methacholine is greater than the first amount of methacholine. In one embodiment, the second amount of methacholine is substantially two times greater than the first amount of methacholine. In one embodiment, the second amount of methacholine is substantially four times greater than the first amount of methacholine.
In one embodiment, a dry powder delivery device includes a mouthpiece including a proximal and distal opening with a first passageway extending therebetween; a spin chamber including a port and an ejection door, wherein the spin chamber is connected to the first air passageway; a housing including a second passageway, wherein the second passageway is connected to the first passageway and further includes an airflow sensor and an adjustable limiting mechanism configured to limit inhaled volume through the second passageway; and a controller operably connected to the airflow sensor and the adjustable limiting mechanism. In one embodiment, the adjustable limiting mechanism is configured to limit inhaled volume through the second passageway to a level between 0.1 and 3.0 liters of air. In one embodiment, the adjustable limiting mechanism is configured to limit flow through the second passageway to a level between 30 and 120 liters of air per minute. In one embodiment, the adjustable limiting mechanism is configured to limit flow through the second passageway to a level between 60 and 90 liters of air per minute. In one embodiment, the adjustable limiting mechanism is controlled by a motor operably connected to the controller. In one embodiment, the adjustable limiting mechanism is a valve. In one embodiment, the dry powder delivery device includes a cartridge including a plurality of dry powder receptacles that are configured to align with the port as the cartridge moves relative to the housing.
The foregoing purposes and features, as well as other purposes and features, will become apparent with reference to the description and accompanying figures below, which are included to provide an understanding of the invention and constitute a part of the specification, in which like numerals represent like elements, and in which:
It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a more clear comprehension of the present invention, while eliminating, for the purpose of clarity, many other elements found in systems and methods for dry powder delivery. Those of ordinary skill in the art may recognize that other elements and/or steps are desirable and/or required in implementing the present invention. However, because such elements and steps are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements and steps is not provided herein. The disclosure herein is directed to all such variations and modifications to such elements and methods known to those skilled in the art.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described.
As used herein, each of the following terms has the meaning associated with it in this section.
The articles “a” and “an” are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, “an element” means one element or more than one element.
“About” as used herein when referring to a measurable value such as an amount, a temporal duration, and the like, is meant to encompass variations of ±20%, ±10%, ±5%, ±1%, and ±0.1% from the specified value, as such variations are appropriate.
“FVC” are used herein means forced vital capacity.
Measurement of the effects of the challenge during bronchial provocation testing is usually performed with a forced vital capacity maneuver. However, alternative measurement techniques such as forced oscillation, body plethysmography, airways resistance, electrical impedance tomography, etc. may also be used to determine the effect of the challenge. Throughout this disclosure “FVC” may represent any of the methods known in the art to determine a change in airway or lung function that reflects the effect of the administration of an airway challenge.
Ranges: throughout this disclosure, various aspects of the invention can be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Where appropriate, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 2.7, 3, 4, 5, 5.3, and 6. This applies regardless of the breadth of the range.
Referring now in detail to the drawings, in which like reference numerals indicate like parts or elements throughout the several views, in various embodiments, presented herein are systems and method for dry powder delivery.
With reference now to the exemplary embodiment shown in
As each capsule 50 is advanced, it is positioned to align with the opening in the spin chamber 112 through a port 113, as shown with more detail in
With reference now to
In one embodiment, at least one sensor 118 is set in an air pathway and is in communication with the user's airflow moving through the system 100 for measuring inspiratory effort. The sensor, such as a pressure or flow transducer, can be attached in or near the spin chamber 112 or the mouthpiece opening 106, or in an alternate pathway in airflow communication with the mouthpiece 104. In certain embodiments, the sensor 118 is used to provide feedback to the user through a performance indicator 120 that is within view to the user during the challenge. In an exemplary embodiment, the performance indicator 120 includes a number of light emitting elements 122, such as light emitting diodes, that light to reflect user performance. Performance can include, for example, a flow based or pressure based reading from the sensor 118. The light emitting elements 122 can be stacked and color coded to provide additional types of feedback information to the user. In certain embodiment, a flow limiter is also utilized to provide inspiratory flow clamping and limit the airflow through the device to control maximum inspiratory flow. For example, in certain embodiments, different sized mouthpieces 104 with various diameter openings are provided to medical technicians, so that a proper flow limit is established during setup phases of the challenge. In other embodiments, the lattice structure 108 is interchangeable, providing a multitude of cross-sectional opening profiles to allow more or less airflow through the mouthpiece 104. Certain embodiments may also limit airflow by adjusting the size of certain airflow pathways within the system 100, such as by using an iris valve to narrow or opening the spin chamber openings 114, 116.
In certain embodiments, an imaging system can utilize a camera to image capsules, while image processing software run by a controller is used to confirm that correct dosages are loaded into each capsule, and that dry powder is sufficiently cleared from capsules following user inhalation. The image processing system could also be used to verify what percentage of a particular dosage has been inhaled following a user inhalation. In certain embodiments, the imaging system includes a dual camera setup for verifying correct doses are loaded into the cartridge or the spin chamber, and for reviewing dry powder levels capsules following inhalation. One or more cameras can be trained on the cartridge, the spin chamber, or other parts of the system that house capsules. In certain embodiments, an image processing system, bar code reader or RFID chip is associated with each capsule and/or the cartridge, and is used to identify that a capsule has been loaded, or otherwise used to verify the contents of the loaded dose.
With reference now to one exemplary embodiment shown in
The volume clamping mechanism of the device is able to address the limitations of other dry powder delivery systems for provocation testing. In order to get dry powders to flow into the airway, it requires that the test subject inhale with a sufficiently high flow that will pull the capsule into the spin chamber and create the vortices that spin the capsule. This flow may be as high as 30 or 120 liters of air per minute. However, if a subject is allowed to inhale at that flow rate without any volume limitation, they may quickly fill their lungs to capacity in less than a few seconds. As previously stated, this filling the lungs to capacity could blunt the response to the challenge of the particles. Therefore there is needed a volume clamping mechanism that allows the test subject to inhale with flow rates greater than 30 liters per minute and yet limits how much air they can inhale in terms of total volume. In one embodiment, the volume limit is set in the control logic of the device. During inhalation through flow sensor 231, the flow is integrated into its volume and when the volume reaches the set limit, valve 234 is closed and no additional air can enter the airway. The timing for the closure of the valve may be adjusted for the anticipatory time so that it is closed at the correct volume, taking into account the time to close. In certain embodiments, the limiting mechanism is configured to limit flow between 60 and 90 liters of air per minute.
As mentioned above, the inhalation diagnostic challenge can include a number of visual and audio feedback mechanisms for the user and/or for the medical professional assisting the user in the challenge. Now with reference to
After the baseline forced vital capacity (FVC) is measured, the system will check for exclusion criteria (
The disclosures of each and every patent, patent application, and publication cited herein are hereby incorporated herein by reference in their entirety. While this invention has been disclosed with reference to specific embodiments, it is apparent that other embodiments and variations of this invention may be devised by others skilled in the art without departing from the true spirit and scope of the invention.
This application claims priority to U.S. provisional application No. 62/219,214 filed on Sep. 16, 2015, incorporated herein by reference in its entirety.
Number | Date | Country | |
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62219214 | Sep 2015 | US |