Patent Application
20190015081
The present invention relates generally to monitoring devices and related components used to measure pulmonary functions, and more particularly to testing for nitric oxide (NO), as well as other markers, associated with monitoring respiratory medical conditions.
Respiratory diseases are some of the most common disorders in the world. Such respiratory diseases include conditions such as chronic obstructive pulmonary disease (COPD), asthma, cystic fibrosis and pulmonary fibrosis. COPD, for example, affects millions of people and is responsible for extensive morbidity and mortality in the United States. COPD is a term used to describe chronic lung diseases characterized by progressive development of airflow limitations that are usually not fully reversible with medication. The common symptoms of COPD include breathlessness, wheezing and a chronic cough.
Asthma is another example of a chronic lung disease with symptoms similar to COPD, such as breathlessness and wheezing, but etiologically distinct from COPD. Asthma is a prevalent health care problem; it affects millions in the United States and around the world. About 40% of patients with asthma can be classified as having moderate to severe asthma and would benefit from more frequent monitoring of their airway inflammation. Although COPD and asthma require different treatments, test results for COPD and asthma often overlap.
Asthma in particular is characterized by an inflammatory reaction in hyper-reactive airways that restrict airflow into the lungs. In recent years, measurement of exhaled nitric oxide (eNO) has been shown to be a non-invasive and complementary tool to other pulmonary function tests in assessing airway inflammation, specifically in subjects with asthma. Accordingly, the presence of eNO has become a well-known, globally accepted biomarker for airway inflammation.
Nitric oxide is produced endogenously in cells by NO synthase and secreted by eosinophils in the distal alveoli. Its production is increased in response to inflammatory cytokines (which is associated with asthmatic episodes), and exhaled NO is thought to be an indirect measurement of airway eosinophilic inflammation. Thus, nitric oxide exhaled from the lower airways (e.g., non-nasal airways) can be correlated with the degree of airway inflammation. Patients with asthma have high levels of NO in their exhaled breath. Nitric oxide levels increase prior to the presence of clinical symptoms and its levels decline in response to appropriate therapy as airway inflammation subsides. These two characteristics make this an ideal biomarker for managing asthma status. For this reason, in 2011, the American Thoracic Society (ATS) issued new guidelines recommending the measurement of exhaled nitric oxide for the diagnosis and management of asthma. A diagnosis of asthma can be made when the level of nitric oxide in exhaled breath exceeds 50 ppb. High eNO levels are also associated with other inflammatory respiratory conditions.
In diagnosing respiratory diseases, a series of tests for eNO may be conducted. For example, point-of-care breath analyzers can provide eNO information to a physician or in a clinical setting, while handheld or portable breath analyzers can provide exhaled nitric oxide information to an individual patient. Details regarding a respiratory monitor useful for the detection of eNO is described in U.S. Patent Publication No. 2015/0250408 A1, titled “Respiratory Monitor,” the entirety of which is incorporated by reference herein. Details regarding a respiratory monitor useful for the detection of eNO also are described in U.S. Patent Publication No. 2017/0065208 A1, titled “Respiratory Monitor,” the entirety of which also is incorporated by reference herein. Respiratory devices using other sensors and other technologies also may test for various other biomarkers in a patient's breath.
For patients attempting to provide physicians monitoring their respiratory conditions, it is not always possible to have access to real-time NO analysis. Under these circumstances, being able to collect one or more breath samples and store them for later analysis is beneficial to monitoring a patient's respiratory status. However, for any later analysis to be accurate and beneficial to the physician's treatment of their patients, the collection of breath samples must be consistent, and the storage of the sample must maintain the sample's integrity. For example, for patients collecting their own breath samples, patients must be able to collect and store the correct portion of their exhaled breath, exhale at the correct flow rate, and do so consistently.
Thus, it is desirable and advantageous to provide an apparatus that permits users to consistently and accurately capture exhaled breath samples and to properly store the collected breath samples for later nitric oxide analysis.
The present invention is generally directed to an apparatus and method for collecting and storing a breath sample for later nitric oxide measurement. In one embodiment, the apparatus comprises an airflow chamber in fluid communication with an inhalation/exhalation portal, as well as in fluid communication with a one-way air inflow portal and an air outflow portal. A flow meter, or pressure gauge, in fluid communication with the airflow chamber can be used to measure the airflow rate within the chamber. The air outflow portal is detachably connected to a breath storage vessel, such as a gas sample bag. Additionally, a filter, or scrubber, can be positioned upstream of the air inflow portal to substantially remove undesirable compounds, such as nitric oxide, during inhalation of air into the lungs. A desiccant may also be positioned upstream of the breath storage vessel to substantially reduce humidity in the breath sample being collected. In an alternate embodiment, the air inflow portal may be omitted where the user need only exhale air from the lungs into the airflow chamber for collection and storage of a breath sample.
In practice, in one embodiment, air is inhaled into the lungs through an airflow chamber via the inhalation/exhalation port via a one-way valve. The inhaled air is then exhaled through the inhalation/exhalation port back into the airflow chamber and into the breath storage vessel. In some embodiments, a three-way valve is placed in fluid communication between the airflow chamber and the breath storage vessel to allow discharge of exhaled breath to either the outside or into the breath storage vessel. In other embodiments, a programmable controller can be placed in electrical connection with the flow meter and the three-way valve to allow the automatic switching of the three-way valve from discharge of the exhaled breath to the outside or collection of the breath into the breath storage vessel, thereby allowing collection of preselected portions of the exhaled breath. In still other embodiments, the flow rate of exhaled breath through the airflow chamber can be controlled automatically through mechanisms that adjust the resistance to the rate of flow that are positioned downstream of the inhalation/exhalation portal to maintain the flow rate within certain parameters. Such mechanisms can include automated needle valves, automated adjustable apertures and the like.
As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, processes, methods, articles, or apparatuses that comprise a list of elements are not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such processes, methods, articles, or apparatuses. Further, unless expressly stated to the contrary, “or” refers to an inclusive “or” but not to an exclusive “or.” For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).
Also, use of “a” or “an” are employed to describe the elements and components of the invention. This is done merely for convenience and to give a general sense of the invention. This description includes one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.
Unless otherwise defined, 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 methods that are similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described herein. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, materials, methods, and examples are illustrative only and not intended to be limiting.
In the following description, numerous specific details, such as the identification of various system components, are provided to understand the embodiments of the invention. One skilled in the art will recognize, however, that embodiments of the invention can be practiced without one or more of the specific details, ordinary methods, components, materials, etc. In still other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of various embodiments of the invention.
Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or work characteristics may be combined in any suitable manner in one or more embodiments.
The present invention allows for collecting a sample of breath into a vessel for later nitric oxide analysis. Referring to
The airflow chamber, air inflow portal, inhalation/exhalation portal, air outflow portal, and discharge portal are dimensioned taking into account pressure, flow, and resistance factors to accommodate the ease of inhaling air through the apparatus and into the lungs, and then expelling the inhaled air from the lungs back into the airflow chamber and into the breath storage vessel. While it is desirable to maintain a low resistance during the inhalation process, the resistance during exhalation of breath from the mouth needs to be sufficient to close the velum. In most instances, the exhalation airflow resistance must be greater than five inches of water to close the velum.
In the below description, the air inflow portal and air outflow portal and the inhalation/exhalation portal are illustrated by reference to specific structures for purposes of describing the invention. Those of skill in the art will recognize alternatives to the specific structures described.
Referring to
Referring more specifically to
Again referring to
In practice, it is desirable to control the flow rate of the exhaled air. Accordingly, feedback on the flow rate of exhaled breath can be monitored by an airflow monitor, such as a flow meter or pressure gauge 11. Flow rates can range from about one liter per minute to about six liters per minute. Preferred flow rates are in general three liters per minute (plus or minus 10%) or ideally between 2.7 liters per minute and 3.3 liters per minute.
In addition, in practice it is often desirable to collect a more desirable portion of the exhaled breath for analysis by discharging a portion of exhaled breath to the outside. Although the times can be adjusted to any amount for collecting the desired portion of breath, it is generally preferred to discharge an initial portion of the exhaled breath to the outside, then collect a subsequent portion in a breath collection vessel. These times most often range from three to seven seconds for discharging air to the outside before collecting the second portion of exhaled breath. For example, to collect a more preferred portion of the exhaled breath, it is often desirable to discard the first portion of the exhaled breath to the outside, e.g. through the discharge portal 4A, and route a second portion of the exhaled breath into the breath storage vessel 9. Referring to
To facilitate the switching of the three-way valve from discharge to collection, the flow meter and the three-way valve can be electrically connected through a controller programmed to switch the three-way valve to discharge the exhaled breath to the outside. For example, the controller can be programmed to discharge exhaled breath to the outside, then switch the valve to direct the breath into the breath storage vessel. In a preferred embodiment, the controller can be programmed to discharge exhaled breath to the outside for approximately 3-7 seconds, then switch the valve to direct the breath into the breath storage vessel for a subsequent 3-7 seconds.
In addition, it is often desirable to automatically control the flow rate of exhaled breath through the airflow chamber to maintain the desired flow rate. This improves consistency as to the collected samples, and improves consistency in flow rates as between different users of the apparatus. Automatically controlling the flow rate through the airflow chamber can be achieved through mechanisms that adjust the resistance to the flow rate that are positioned downstream of the inhalation/exhalation portal to maintain the flow rate within certain parameters, e.g., a flow rate of approximately three liters per minute. Such mechanisms can include automated needle valves, automated adjustable apertures and the like. A programmable controller in electrical communication with a flow meter and the flow restriction mechanism can be employed to electrically control the flow rate through the airflow chamber.
As for additional details pertinent to the present invention, materials and manufacturing techniques may be employed as within the level of those with skill in the relevant art. The same may hold true with respect to method-based aspects of the invention in terms of additional acts commonly or logically employed. Also, it is contemplated that any optional feature of the inventive variations described may be set forth and claimed independently, or in combination with anyone or more of the features described herein. The breadth of the present invention is not to be limited by the subject specification, but rather only by the plain meaning of the claim terms employed.
This disclosure is sufficient to enable one of ordinary skill in the art to practice the invention, and provides the best mode of practicing the invention presently contemplated by the inventor. While a full and complete disclosure is made of specific embodiments of this invention, the invention is not limited by the exact construction, dimensional relationships, and operation shown and described. Various modifications, alternative constructions, design options, changes and equivalents will be readily apparent to those skilled in the art and may be employed, as suitable, without departing from the spirit and scope of the invention. Such changes might involve alternative materials, components, structural arrangements, sizes, shapes, forms, functions, operational features and the like.
This application claims the benefit of U.S. Provisional Application No. 62/533,470 filed on Jul. 17, 2017, the subject matter of which is herein incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62533470 | Jul 2017 | US |
