Patent Application
20070240987
Throughout the description, similar reference numbers may be used to identify similar elements.
It will be readily understood that the components of the embodiments as generally described and illustrated in the Figures herein could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of various embodiments, as represented in the Figures, is not intended to limit the scope of the present disclosure, but is merely representative of various embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment.
Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention.
Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language 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, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
In the following description, numerous specific details are provided, such as examples of housings, barriers, chambers etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations such as vacuum sources are not shown or described in detail to avoid obscuring aspects of the invention.
Additionally, the physical size and weight of the sensing apparatus 100 may vary depending on the implementation. In some embodiments, the sensing apparatus 100 is physically small and light enough to be lifted and carried around by one person. For example, the sensing apparatus 100 may weigh less than ten (10) pounds (lbs). In another example, the sensing apparatus 100 may weight less than two (2) lbs. In regard to size, some embodiments of the sensing apparatus 100 may be less than about 300 cubic centimeters (cc) in volume. Other embodiments of the sensing apparatus are less than about 50 cc, and other embodiments are less than about 20 cc. Still other embodiments may be less than about 5 cc and some less than about 2 cc. Although the size and weight of the sensing apparatus 100 facilitates relatively easy use by individuals, use of the sensing apparatus 100 by a physician for one or more patients is not precluded.
In one embodiment, the catalyst 104 conditions a chemical characteristic of the exhaled breath. In other words, the catalyst 104 pretreats the exhaled breath before it is directed to the sensing electrode 106. There are many types of catalysts 104, or combinations of catalysts 104, that may be implemented. For example, some catalysts 104 change the composition of the exhaled breath in order to minimize cross-sensitivity. Thus, the catalyst 104 may facilitate oxidation of carbon-monoxide (CO) to carbon dioxide (CO2), oxidation of hydrocarbons to CO2 and steam (H2O), absorption of sulfur dioxide (SO2), and oxidation of ammonia (NH3) to nitrogen (N2) and steam (H2O). For ease of description, these and other forms of catalytic processes may be categorized into four general categories: conversion, oxidation, absorption, and equilibrium. However, it should be noted that embodiments of the catalyst 104 may implement one or a combination of these catalytic processes, and do not necessarily implement all of these catalytic processes.
In one embodiment, the catalyst 104 is an oxidation catalyst such as platinum, ruthenium (IV) oxide (RuO2) or cobalt oxide (CO3O4) which functions to oxidize hydrocarbons and convert CO to CO2. Other catalysts 104 also may be used such as, for example, the catalysts described and mentioned in U.S. patent application Ser. No. 11/137,693, filed May 25, 2005, and U.S. Provisional Application No. 60/574,622, filed May 26, 2004, both of which are incorporated by reference herein in their entirety. In another embodiment, other pretreatment elements 104 are used to remove unwanted components from the exhaled breath prior to the exhaled breath coming into contact with the sensing electrode 106. For example, the pretreatment element 104 may accept hydrocarbons and CO and yield N2, O2, NO, CO2, and H2O (e.g., water). As a specific example, the pretreatment element 104 may include an alumina (Al2O3) felt. In one embodiment, the pretreatment element 104 such as a catalyst is porous so that the flow of the exhaled breath is not significantly obstructed by the pretreatment element 104. In this way, the sensing apparatus 100 is configured to be effective with just a small volume of exhaled breath over a short amount of time.
After the exhaled breath is pretreated by the catalyst 104 or another pretreatment element, the exhaled breath is then conducted to the sensing electrode 106. In one embodiment, the sensing electrode 106 is a highly sensitive element that detects very low levels (e.g., less than 10 ppb) of NO in the exhaled breath. Alternatively, the sensing electrode 106 may detect another component of nitrogen oxide (NOX) such as nitrogen dioxide (NO2).
Various types of sensing electrodes 106 may be used in different embodiments of the sensing apparatus 100. In one embodiment, the sensing electrode 106 is implemented using a mixed potential technology. In some embodiments, the sensing electrode 106 is similar to an exhaust gas sensor. In other embodiments, the sensing apparatus 100 includes multiple sensing electrodes 106 such as an oxygen sensor, a NOX sensor, or another type of sensor. Various exemplary sensor electrodes 106 are described in more detail in U.S. Pat. No. 6,764,591, issued Jul. 20, 2004, and U.S. Pat. No. 6,843,900, issued Jan. 18, 2005, both of which are incorporated by reference herein in their entirety. Additionally, other exemplary sensor electrodes 106 are described in more detail in U.S. patent application Ser. No. 11/182,278, filed Jul. 14, 2005, which is incorporated by reference herein in its entirety.
The sensing electrode 106 generates an electrode signal (e.g., a voltage signal) in response to detecting a corresponding component of NOX, or another gas, depending on the type of sensing electrode 106 that is implemented. Alternatively, if two or more sensing electrodes 106 are implemented, each sensing electrode 106 may generates its own electrode signal. For example, an embodiment of the sensing apparatus 100 which implements a NO sensing electrode 106 and an oxygen sensing electrode 106 may use two electrode signals-one generated by the NO sensing electrode 106 and the other generated by the oxygen sensing electrode 106. Once the electrode signal is generated, the exhaled breath exits the sensing apparatus 100 through the outlet 108.
The electrode signal generated by the sensing electrode 106 is subsequently transmitted to the electronic circuitry 110, which determines a level of NO in the exhaled breath. In one embodiment, the electronic circuitry 110 converts the electrode signal to a measured NO reading that can be displayed on the display 112. Alternatively, the electronic circuitry 110 may provide another type of indicator, scale, or message to the display 112 to be conveyed to a user. For example, the display 112 may display a quantitative indicator such as a NO measurement reading. In another embodiment, the display 112 may display a qualitative indicator such as a message to convey the presence and/or severity (e.g., low or high NO levels) of asthma. Other exemplary types of messages displayed by the display 112 may include an indication that medication should be obtained, suggested dosages, prescription information, treatment instructions, or instructions to contact a physician or seek emergency care.
Thus, embodiments of the sensing apparatus 100 allow for measurements and/or readings of breath components with normal exhalation and without sustained exhalation. In other words, the sensing apparatus 100 can take readings or measure breath components with small volumes of exhaled breath, without the need for holding chambers and the like. Accordingly, the sensing apparatus 100 can use a patient's natural breathing pattern to take NO measurements without the use of additional exhalation force over a sustained period of time.
It should be noted that
It should also be noted that the chamber 114 is not necessarily a holding chamber to hold the exhaled breath for a specific amount of time. Rather, the chamber 114 may or may not be a holding chamber. In some embodiments, the chamber 114 is simply a conduit or passageway for the exhaled breath to pass through as it travels from the pretreatment element 104 to the outlet 108, for example, while the sensing electrode 106 generates the corresponding electrode signal. In one embodiment, the volume of the chamber 114 is approximately 300 cc. In another embodiment, the volume of the chamber 114 is less than about 50 cc. Alternatively, the volume of the chamber 114 is less than about 20 cc. In one embodiment, the chamber 114 is less than 5 cc. In another embodiment, the chamber 114 is less than 2 cc. These volumes may also be applicable to the entire sensing apparatus 100.
In one embodiment, the electrode heater 116 preheats the sensing electrode 106 to a predetermined temperature prior to operation of the sensing apparatus 100. Alternatively, the electrode heater 116 may preheat the sensing electrode 106 to an operating temperature range. The predetermined temperature or the operating temperature range depends on the type of sensing electrode 106 that is used. For example, the electrode heater 116 may preheat the sensing electrode 106 to an operating temperature range of about 450-550° C. for a sensing electrode 106 configured to detect NO in the exhaled breath. As another example, the electrode heater 116 may preheat the sensing electrode 106 to an operating temperature range of about 700-800° C. for a sensing electrode 106 configured to detect oxygen in the exhaled breath. As another example, the electrode heater 116 may preheat the sensing electrode 106 to an operating temperature range of about 300-1000° C. for other types of sensing electrodes 106. Other temperatures and temperature ranges may be used, as explained in the references incorporated above, depending on the type of sensing electrode 106 implemented. In some embodiments, multiple electrode heaters 116 may be implemented for multiple corresponding sensing electrodes 106. The amount of time allocated or consumed to preheat the sensing electrode 106 depends on the type of sensing electrode 106 and electrode heater 116 implemented, as well as the general construction of the sensing apparatus 100. In a similar manner, the catalyst heater 118 heats the pretreatment element 104 such as a catalyst to a predetermined temperature, or within a temperature range, to enhance the effectiveness of the pretreatment element 104.
In one embodiment, the electronic circuitry 110 includes various electronic components, including the electronic memory device 122. Different embodiments of the electronic circuitry 110 may implement the electronic memory device 122 using different types of data memory or data storage technology, including but not limited to read only memory (ROM), random access memory (RAM), flash memory, removable memory media, and so forth. Although not shown, other electronic components may be implemented in the electronic circuitry 110. For example, some embodiments of the electronic circuitry 110 include a processor such as a general purpose processor, a digital signal processor (DSP), a microprocessor, a field programmable gate array (FPGA), or an application specific integrated circuit (ASIC). It should be noted that the implementation of the electronic circuitry 110, including the electronic memory device 122, is not limited to a particular configuration, arrangement, or technology.
In one embodiment, the electronic memory device 122 is configured to store various types of data. For example, the electronic memory device 122 may store historical data 124, user preferences 126, and a lookup table 128. Other embodiments may store additional data or other types of data. In one embodiment, the historical data 124 include data to describe historical NO levels for a particular user. In another embodiment, the user preferences 126 include default and/or user-specific settings for the sensing apparatus 100. For example, a user may indicate whether the user prefers to receive messages about quantitative or qualitative evaluations, or both, of the user's NO levels.
In one embodiment, the lookup table 128 stores data to translate between a digital signal, which is associated with the electrode signal, and a NO value corresponding to the digital signal. For example, where the sensing electrode 106 generates an analog voltage signal as the electrode signal, and a digital-to-analog converter (DAC) (not shown) converts the electrode signal to a digital signal, which the electronic circuitry 110 may use to index the lookup table 128 to determine what NO level corresponds to the electrode signal.
It should be noted that the type of lookup table 128 implemented may depend on the type of electrode signal (or signals) generated by the sensing electrode 106 (or sensing electrodes 106). For example, where a NO sensing electrode 106 is implemented, an embodiment of the lookup table 128 outputs a NO measurement level based on the digital signal corresponding to the analog NO electrode signal. Alternatively, where a NO2 sensing electrode 106 is implemented, an embodiment of the lookup table 128 outputs a NO measurement level based on the digital signal corresponding to the analog NO2 electrode signal. In another embodiment, where both NO and oxygen sensing electrodes 106 are implemented, an embodiment of the lookup table 128 outputs a NO measurement level based on a combination (e.g., ratio) of the digital signals corresponding to the analog NO and oxygen electrode signals. It should be noted that such combinations of multiple signals (e.g., NO and oxygen electrode signals) may be combined in either the analog domain or the digital domain.
Moreover, although some embodiments of the lookup table 128 are used to output NO measurement levels directly, other embodiments of the lookup table 128 may be used to output qualitative indicators, rather than quantitative indicators. Furthermore, other embodiments of the electronic circuitry 110 may use another technology instead of the lookup table 128 stored in the electronic memory device 122.
Although several components of the sensing apparatus 100 are shown and described above with reference to
The exhaled breath received by the receiver 134 is then conducted to the inlet 102 of the sensing apparatus 100 through the conduit 136. In one embodiment, the conduit 136 is a tube that does not absorb NO, or absorbs very little NO. For example, the conduit 136 may have an interior surface material such as TEFLON or silicone to deflect substantially all of the NOX in the exhaled breath. Alternatively, the conduit 136 may have another material on the interior surface. Additionally, the NOX-resistant material may be integral to the conduit 136 or may be coated or otherwise applied on the interior surface of the conduit 136.
In the illustrated method 140, the sensing apparatus 100 receives 142 a volume of exhaled breath from a source such as a patient. In one embodiment, the exhaled breath is received through the inlet 102. In a further embodiment, the exhaled breath is first received through the receiver 134 and the conduit 136. The pretreatment element 104 then pretreats 144 the exhaled breath, for example, with a pretreatment catalyst, as described above. In one embodiment, the pretreatment element 104 is porous and the exhaled breath flows through the pretreatment element 104 to the sensing electrode 106.
In one embodiment, the pretreated air is specifically conducted to a chamber 114. The sensing electrode 106 is coupled to the chamber 114 and detects 146 NO in the pretreated breath. Upon detection of NO in the pretreated breath, the sensing electrode 106 generates 148 an electrode signal based on the detected NO. In one embodiment, the sensing electrode 106 transmits the electrode signal to the electronic circuitry 110, which converts 150 the electrode signal to a NO level. The sensing apparatus 100 then displays 152 a message indicative of the amount of NO in the exhaled breath. As described above, the displayed message may be a quantitative indicator, a qualitative indicator, or a combination of quantitative and qualitative indicators. The illustrated method 140 then ends.
It should be noted that the operations of receiving 142 a volume of exhaled breath, pretreating 144 the exhaled breath, and displaying 152 a message to the user are substantially similar to the corresponding operations in the method 140 of
Upon detection of NO2 in the pretreated breath, the sensing electrode 106 generates 164 an electrode signal based on the detected NO2. In one embodiment, the sensing electrode 106 transmits the electrode signal to the electronic circuitry 110, which converts 166 the electrode signal to a NO level. The remaining operations of the method 160 are similar to the operations described above with reference to the method 140 of
It should be noted that the operations of receiving 142 a volume of exhaled breath, pretreating 144 the exhaled breath, and displaying 152 a message to the user are substantially similar to the corresponding operations in the method 140 of
In the illustrated method 180, the user turns on the sensing apparatus 100, including turning on 182 the electrode heater 116. This allows the electrode heater 116 to preheat, as described above. The user also may set 184 display settings or other user preferences upon initiation of the sensing apparatus 100. The user then waits 186 for the electrode heater 116 to preheat to the operating temperature range of the sensing electrode 106. In some embodiments, it may take only a few minutes for the electrode heater 116 to preheat the sensing electrode 106. Once the sensing electrode 106 is determined 188 to be within the operating temperature range, the user may receive 190 a ready indication from the sensing apparatus 100. For example, the sensing apparatus 100 may display a ready indicator on the display 112, turn on a ready indicator LED, generate an audible ready tone, or implement another type of ready indicator.
After the sensing apparatus 100 is ready and the sensing electrode 106 is preheated, the user then exhales 192 into the sensing apparatus 100. In one embodiment, the user exhales directly into the inlet 102 or the receiver 134. The sensing apparatus 100 then performs as described above, and the user views 194 a message on the display 112. In one embodiment, the message is a quantitative indicator to indicate a level of NO in the exhaled breath. Alternatively, the message may be a qualitative indicator to provide a qualitative evaluation or assessment of the user's level of NO in the exhaled breath. The illustrated method 180 then ends.
Although the operations of the method(s) herein are shown and described in a particular order, the order of the operations of each method may be altered so that certain operations may be performed in an inverse order or so that certain operations may be performed, at least in part, concurrently with other operations. In another embodiment, instructions or sub-operations of distinct operations may be implemented in an intermittent and/or alternating manner.
Although specific embodiments of the invention have been described and illustrated, the invention is not to be limited to the specific forms or arrangements of parts so described and illustrated. The scope of the invention is to be defined by the claims appended hereto and their equivalents.
This application claims the benefit of U.S. Provisional Application No. 60/792,308, filed on Apr. 14, 2006, which is incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60792308 | Apr 2006 | US |
