Determining exhaled air temperature

Abstract

Methods and devices useful for determining exhaled air temperature (EBT) are disclosed. An apparatus for determining EBT includes a conduit defining an air passage, a heat collector located within the air passage, a mouthpiece associated with the conduit such that exhaled air directed into the air passage by the mouthpiece can exchange heat with the heat collector, a temperature meter configured to determine a temperature of the heat collector, and a controller configured to control the temperature of the heat collector. A controller is for receiving the temperature of the heat collector and for calculating a temperature indicative of the temperature of the exhaled air.

Description

Related applications

[0001] This application is granted priority to U.S. Provisional Patent Application No. 63 / 464,229, filed May 5, 2023, which is incorporated herein by reference as if fully set forth herein. Field and background of the invention

[0002] In some embodiments, the present invention relates to a method and apparatus for measuring exhaled gas temperature (EBT).

[0003] The use of exhaled breath temperature (EBT) measurement, for example, in the diagnosis of pathology, has been disclosed in the following literature: a. Piacentini, Peroni, Crestani, Zardini, Bodini, Costella, Boner, Clin Exp Allergy, 2007, Vol. 37, pp. 415-419; b. Popov, Dunev, Kralimarkova, Kraeva, DuBuske, Respiratory Medicine, 2007, Vol. 1010, pp. 2044-2050; c. Popov, Kralimarkova, Tzachev, Dunev, Dimitrov, and Gill, EBT article for the IEEE Special Issue of IEEE Sensors Journal, February 2010; d. Popov, Kralimarkova, and Dimitrov, Breath, Vol. 8, No. 3, 2012, pp. 187-192; e. Vermeulen, Barreto, La Penna, Martella, Biagiarelli, Villa, *Journal of Asthma*, 2014, pp. 1-8; f. Lázár, Bikov, Martinovsky, Gálffy, Losonczy and Horváth, Journal of Respiratory Research (JBreath Res), 2014, Vol. 8, No. 046002, pp. 1-9; g. Harnawan, Mariati, Assegaf, *Journal of Physics: Cond. Series*, 2017, Vol. 853, No. 012021; and h. Tufvesson, Nilsson, Popov, Hesselstrand, Bjermer, *European Journal of Clinical Respiratory Medicine*, 2020, Vol. 7, No. 1, 1747014.

[0004] Methods and apparatus suitable for determining EBT have been disclosed, for example, in patents and patent applications, such as: US 8,323,207, US 2004 / 0039295, US 2010 / 0063409, US 2013 / 0030316, US 2015 / 0342502, US2017 / 0156633, US 2018 / 0325421, US 2019 / 0175065, US 2021 / 0212595, and EP 2745775 and WO 2009 / 006655.

[0005] Having an apparatus for measuring EBT would be useful, having at least one advantage over known apparatuses for measuring EBT. Invention Overview

[0006] In some embodiments, the present invention relates to a method and apparatus suitable for measuring the temperature of exhaled gas.

[0007] According to one aspect of some embodiments taught herein, an apparatus suitable for measuring exhaled gas temperature (EBT) is provided, comprising: A conduit that defines an air passage; The heat collector is located inside the air passage. The mouthpiece is functionally associated with the conduit and is configured such that when a person exhales air through their mouth (usually but not always, while simultaneously wrapping their lips around the mouthpiece), the mouthpiece guides the exhaled air into the air passage, allowing the exhaled air to exchange heat with the collector. A temperature determiner is configured to measure the temperature of the solar collector at least once during exhalation through the mouthpiece; and The controller, which includes a computer processor and a memory, is used to receive the temperature of the solar collector as measured by a temperature sensor, and to subsequently calculate an indication temperature that indicates the temperature of the exhaled air, the calculation being based on the temperature of the solar collector as measured by the temperature sensor.

[0008] According to the teachings of this article, the indicated temperature is considered to be EBT.

[0009] As used herein, the phrase “exhaled air can exchange heat with the collector” and its variations mean that the device is configured such that the collector heats or cools when there is a temperature difference between the collector and the exhaled air flowing through the air passage.

[0010] In some embodiments, the controller is configured such that the indicated temperature of the exhaled air is calculated to be the same as the temperature of the collector as measured by a thermal measuring device; that is, it is acceptable that the temperature of the exhaled air (EBT) is substantially the same as the temperature of the collector. In such embodiments, it should be appreciated that the collector temperature measured by the thermal measuring device is not exactly the true temperature of the exhaled air, but is close enough to be diagnostically useful, particularly when the various measurements are compared with each other and / or processed by a processor, providing, for example, an average or trimmed mean of the measured EBT. In some embodiments, the controller is configured to calculate the indicated temperature of the exhaled air based on the temperature of the collector measured by the thermal measuring device, but the indicated temperature is corrected for other factors, such as taking into account the humidity of the exhaled air, and / or modified by correction factors to account for known and / or expected errors.

[0011] In some embodiments, the device further includes a display functionally associated with the controller to display the measured temperature and / or the calculated indicated temperature of the exhaled air. The display is any suitable component for displaying the measured temperature and / or indicated temperature in a human-perceptible manner, such as an LED, LCD, or plasma display physically or wirelessly associated with the controller, for example, the display screen of a suitably configured smartphone, tablet, or computer, or a display screen that is an integral part of the device.

[0012] In some embodiments, the device further includes a memory functionally associated with the controller to store the measured temperature and / or the calculated indicated temperature. The memory is any suitable component known in the computer field for storing data, such as magnetic or electronic memory, like the memory of a suitably configured smartphone, tablet, or computer, or memory that is an integral part of the device.

[0013] In some embodiments, the device further includes a transmitter (as used herein, the term "transmitter" includes "transceiver") functionally associated with the controller to transmit the measured temperature and / or the calculated indicated temperature. Any suitable transmitter, wired or wireless, such as an infrared transmitter, Li-Fi, or radio frequency transmitter, such as a telephone (any suitable generation, such as 4G, 5G, LTE, LoRa, DASH7), Wi-Fi®, Bluetooth®, NFC, Zigbee, can be used. Such transmitters are typically configured to transmit to remote devices, such as appropriately configured devices (such as smartphones, tablets, computers, or the cloud).

[0014] In some embodiments, the device is configured to display and / or store and / or transmit additional information to a remote device, such as air humidity (in some embodiments, the device includes a component for measuring humidity in an air passage), air pressure (in some embodiments, the device includes a pressure sensor for measuring air pressure within an air passage), ambient air temperature (in some embodiments, the device includes a component for measuring ambient air temperature), flow rate (in some embodiments, the device includes a flow detector for measuring the flow rate through the air passage), or other such information.

[0015] In some embodiments, the temperature sensor is configured to measure the temperature of the collector multiple times during a single exhalation through the mouthpiece. In some such embodiments, the temperature sensor is configured to measure the temperature of the collector at least once every two seconds, at least once per second, and even at least twice per second. In preferred embodiments of this type, the controller is configured to calculate a corresponding indicated temperature for a plurality of received measured temperatures. In even more preferred embodiments of this type, the device is configured to sequentially display and / or store and / or transmit a plurality of measured temperatures and / or indicated temperatures (i.e., in any manner that allows identification of a given temperature, a previous temperature, and a subsequent temperature, such as storing a plurality of measured temperatures and / or a plurality of indicated temperatures as a series, an array, or associating / marking a plurality of measured temperatures and / or a plurality of indicated temperatures with a serial number). In some embodiments, the device includes a component for determining the start time of exhalation, displaying and / or storing and / or transmitting a given indicated temperature or measured temperature in association with a timestamp indicating the time after the start of exhalation when the corresponding indicated temperature was measured. In such embodiments, each such measured and / or indicated temperature corresponds to the measured and / or indicated temperature of the exhaled air at a different stage of exhalation. In some embodiments, EBT is measured multiple times at each stage of exhalation.

[0016] It is known that when a person begins to exhale, the first portion of the air inhaled through the mouth into the mouthpiece and air passage is the air present in the oral cavity, followed by air from the larynx, from the trachea, and then from the lungs (gradually from the more proximal parts of the lungs to the more distal parts). Embodiments such as those described above, in which the temperature of the collector is measured multiple times during exhalation, allow for the identification of the temperature of different portions of the exhaled air. In some cases, the identification of the temperature of different portions of the exhaled air is diagnostically useful; for example, it can indicate the medical condition of the corresponding part of the subject's respiratory system.

[0017] In some embodiments, the temperature measuring device and controller are configured to measure the temperature of the collector for a predefined or variable number of stages for a single exhalation or multiple exhalations.

[0018] In some embodiments, the device includes: A conduit assembly, comprising at least a conduit and a collector; and The main component, which includes other parts of the device, The catheter assembly and body assembly can be reversibly separated from the connected state of the device used to determine the EBT to a disconnected state. In such embodiments, the catheter assembly and body assembly can be separated to a disconnected state or connected to a connected state, thereby allowing, for example, simple cleaning or replacement of the used catheter assembly. In some such embodiments, the nozzle is a component of the body assembly. Alternatively, in some such embodiments, the nozzle is a component of the catheter assembly.

[0019] In some embodiments, the nozzle is integrally formed with the catheter.

[0020] In some embodiments, the collector is physically connected to a duct.

[0021] In some embodiments, the inner wall of the duct near the collector has a thermal conductivity of no more than about 0.5 W / (m K).

[0022] The size and shape of the mouthpiece are any suitable size and shape that allows a person to exhale air through the mouth into the mouthpiece. Such sizes and shapes are well known in a variety of fields, including musical instruments and pulmonary medical devices. Specific known mouthpieces include those of the devices described in US11,719,101 and WO2023 / 081489.

[0023] The size and shape of the air passage can be any suitable size and is usually defined by the inner wall of the duct.

[0024] In the longitudinal direction, the shape of the air passage can be any suitable shape, including J-shaped, longitudinally curved, and straight.

[0025] The proximal portion of the air passage, from the mouthpiece into which exhaled breath enters the air passage to the distal end of the collector, preferably has a constant cross-sectional area and shape. The cross-sectional shape of the air passage is preferably without any vertices, for example, circular, elliptical, or oval. In a preferred embodiment, the proximal portion of the air passage is substantially a straight cylinder, and its cross-sectional shape is preferably without any vertices, and preferably circular.

[0026] The cross-sectional area of ​​the proximal portion of the air passage can be any suitable area. In a preferred embodiment, the cross-sectional area of ​​the proximal portion of the air passage is at least about 0.2 cm². 2 (For example, a circular cross-section with a diameter of 0.5 cm), and more preferably at least about 0.8 cm. 2(For example, a circular cross-section with a diameter of 1 cm). In a preferred embodiment, the cross-sectional area of ​​the proximal portion of the air passage is no greater than approximately 12.6 cm². 2 (For example, a circular cross-section with a diameter of 4 cm), and more preferably no larger than about 3.2 cm. 2 (For example, a circular cross-section with a diameter of 2cm).

[0027] The length of the proximal portion of the air passage is any suitable length, and this length is generally determined to make the device sized for human use. In some preferred embodiments, the length of the proximal portion of the air passage is not less than about 1 cm, and even not less than about 2 cm. In some preferred embodiments, the length of the proximal portion of the air passage is not greater than about 15 cm, and even not greater than about 10 cm.

[0028] The cross-sectional shape of the distal portion of the air passage downstream of the far end of the collector can be any suitable shape, although usually, for the sake of simplifying manufacturing, the cross-sectional shape of the distal portion of the air passage is substantially the same as that of the proximal portion.

[0029] The cross-sectional dimensions of the distal portion of the air passage can be any suitable size, but preferably, the cross-sectional dimensions of the distal portion of the air passage are approximately the same as or larger than the cross-sectional dimensions of the proximal portion of the air passage.

[0030] The length of the distal portion of the air passage is any suitable length and is generally determined to make the device sized for ease of human use and to protect the collector from external factors that may affect its temperature measurement. In some preferred embodiments, the length of the distal portion of the air passage is not less than about 1 cm, and even not less than about 2 cm. In some preferred embodiments, the length of the distal portion of the air passage is not greater than about 15 cm, and even not greater than about 10 cm. As described below, in some embodiments, the distal portion of the air passage includes a one-way valve to prevent air from flowing back towards the collector.

[0031] In some embodiments, the collector has a three-dimensional shape. In some such embodiments, the collector is hollow and has an internal volume. In some such embodiments, the device includes at least one hole (in a preferred embodiment, multiple holes) in the surface of the collector to allow exhaled air to enter the internal volume of the collector. Additionally or alternatively, in some embodiments, ribs of thermally conductive material are located within the internal volume of the collector, thereby allowing rapid heat transfer throughout the collector and helping to ensure that different parts of the collector have the same temperature.

[0032] In some embodiments, the collector comprises a sheet. In some embodiments, the collector is a sheet.

[0033] In some embodiments, the solar collector includes wire. In some embodiments, the solar collector is wire. In some embodiments, the wire is shaped into a 3D form.

[0034] In some embodiments, the device further includes a humidity sensor configured to measure the humidity of exhaled air flowing through the duct and to provide the measured humidity to a controller. Such embodiments can be implemented using any suitable known humidity sensor. In some embodiments, the controller is configured to calculate an indicated temperature, taking into account the humidity of the exhaled air, using the humidity of the exhaled air received from the humidity sensor and a corresponding temperature measured by a temperature sensor for the collector. Determining the temperature of a gas by modifying the measured gas temperature to account for the gas's humidity is well known to those skilled in the art.

[0035] In some embodiments, the device further includes a pressure sensor configured to measure the pressure of exhaled air in the air passage and provide the measured pressure to the controller. Any suitable pressure sensor can be used to implement such an embodiment.

[0036] In some embodiments, the apparatus further includes a flow detector configured to detect airflow through an air passage and provide an indication to a controller of airflow within the air passage. Any suitable flow detector may be used to implement such embodiments, including flow detectors such as those described in US11,179,101 (belonging to one of the inventors) and PCT Publication WO2023 / 081489 (belonging to the applicant). In some such embodiments, the flow detector is configured to determine the airflow rate through the air passage, and in some such embodiments, the determined airflow rate is provided to a controller. In some embodiments, the air flow detector is configured to determine an airflow parameter and provide the determined parameter to a controller.

[0037] In some embodiments, the device further includes components for determining when air inhalation begins and providing an indication to the controller that air inhalation has begun. In some such embodiments, such components are pressure sensors and / or flow detectors and / or temperature sensors and / or other components.

[0038] In some embodiments, the device further includes components for determining when air is inhaled into the air passage and providing an indication to the controller that air is inhaled into the air passage. In some such embodiments, such components are pressure sensors and / or flow detectors and / or other components.

[0039] In some embodiments, the device further includes an ambient air temperature sensor to measure the temperature of the ambient air (i.e., outside the device). In some embodiments, the ambient air temperature sensor is configured to provide the measured ambient temperature to the controller. Such embodiments can be implemented using any suitable temperature sensor, such as a suitable thermometer.

[0040] In some embodiments, the device is configured to prevent air from flowing back through the air passages of the collector. Specifically, such a configuration ensures that ambient air or exhaled air that has already passed through the collector does not flow back through it. Such backflow could alter the temperature of the collector and thus potentially distort temperature measurements. In some such embodiments, the device includes a one-way valve that prevents air from flowing back through the air passages of the collector.

[0041] In some embodiments, the device further includes a transmitter configured to communicate with a remote device (in some embodiments a transmitter that is not a receiver, and in a preferred embodiment a transceiver), wherein the transmitter is selected from the group consisting of wired transceivers, infrared transceivers, radio frequency transceivers, and Li-Fi transceivers.

[0042] In some embodiments, the device also includes self-calibrating hardware and software / firmware configured to provide temperature measurements.

[0043] A device that has a physical connection between the solar collector and the temperature measuring instrument (contact temperature measurement). In some embodiments, the solar collector is in physical contact with a temperature sensor, which serves as a temperature measuring device, and this physical contact provides thermal conduction between the solar collector and the temperature sensor. In some such embodiments, the temperature sensor includes a component selected from the group consisting of thermocouples, thermistors, and integrated circuits.

[0044] In some embodiments, the temperature sensor is in wired communication with electronic circuitry, which is a component of a temperature measuring device that determines the temperature of the solar collector based on information received from the temperature sensor via wired communication. In some embodiments, the electronic circuitry is a component of a controller. Alternatively, in some embodiments, the electronic circuitry is a component separate from but functionally associated with the controller.

[0045] In some embodiments, the device includes: The conduit assembly includes a conduit, a collector, and a temperature sensor; and The main component includes electronic circuitry (and preferably also includes a controller). The conduit assembly and the main body assembly can be reversibly separated from the connected state to the disconnected state. In the connected state, there is wired communication between the temperature sensor and the electronic circuit, enabling the device to measure EBT. In the disconnected state, there is no wired communication between the temperature sensor and the electronic circuit.

[0046] A device with no physical connection between the collector and the temperature measuring instrument (non-contact temperature measurement). In some embodiments, the temperature measuring device includes a non-contact thermometer having a detection window positioned to receive IR radiation emitted from the location of the collector in the air channel as exhaled air passes through the air channel.

[0047] In some embodiments, the detection window of the non-contact thermometer is located outside the air passage. In such embodiments, typically the entire thermometer is located outside the air passage. In some such embodiments, at least a portion of the conduit is transparent to IR radiation, such that during exhalation into the mouthpiece, IR radiation emitted from the collector passes through the IR-transparent portion of the conduit to be received by the detection window of the non-contact thermometer.

[0048] In some embodiments, the portion of the catheter that is transparent to IR radiation (e.g., an IR-transparent window) is smaller than the entire catheter.

[0049] In some embodiments, the entire conduit is substantially transparent to IR radiation.

[0050] In some embodiments, the device includes: The conduit assembly includes conduits and a collector; and The main components include a non-contact thermometer (and preferably also a controller). The conduit assembly and the main body assembly are reversibly separable from a connected state and a disconnected state. In the connected state, the detection window of the non-contact thermometer is positioned to receive IR radiation emitted from the location of the collector in the air channel as exhaled air passes through the air channel, enabling the device to be used to measure EBT.

[0051] In some embodiments, the solar collector is fixedly installed within an air duct.

[0052] In some alternative embodiments, the collector can move within the air passage, but when air is inhaled through the mouthpiece into the air passage, the collector is positioned within the air passage to allow IR radiation from the collector to enter the detection window of the non-contact thermometer. One embodiment of such a device is described in PCT publication WO2023 / 081489. Figure 1A and Figure 1BThe device is a variation of the one described herein, which is incorporated herein by reference at least for the purposes of supporting these embodiments. In this device, the movable part 28 is typically in a first position, but when the user exhales into the mouthpiece of the device, the exhaled air moves the movable part 28 to a second position. In a variation of the device that is an embodiment of the device taught herein, the movable part is a collector, for example, a metal (such as aluminum, silver, copper, or gold) sphere, preferably a hollow sphere, preferably having a heat-conducting string running from one side of the sphere through the hollow portion, and the IR transparent detection window of the non-contact thermometer is positioned to receive IR radiation emitted from the location of the collector in the air channel (which is the second position of the collector) as the exhaled air passes through the air channel.

[0053] According to one aspect of some embodiments taught herein, a method for determining exhaled gas temperature (EBT) is also provided, the method comprising: a. Providing an apparatus, the apparatus comprising: A duct that defines an air passage, in which the solar collector is located, and The nozzle is in fluid communication with an air passage (e.g., any suitable embodiment of the device taught herein). b. During the exhalation of air from the subject's mouth through the mouthpiece and into the air passage, the exhaled air exchanges heat with the collector (causing the collector to heat or cool, depending on the relative temperatures of the exhaled air and the collector), and the temperature of the collector is measured at least once during exhalation; and c. Calculate the indicated temperature, which indicates the temperature of the exhaled air, based on the temperature of the collector as measured by a temperature measuring device.

[0054] As described above with reference to the apparatus taught in this article, the indicated temperature is considered to be EBT.

[0055] In some embodiments, the method further includes measuring the humidity and / or pressure of the exhaled air, and during “c”, indicating that the temperature is corrected for other factors (e.g., taking into account the humidity of the exhaled air) and / or modified by a correction factor to account for known and / or expected inaccuracies.

[0056] In some embodiments, the method further includes recording (e.g., on an electronic or magnetic medium), transmitting (wired or wireless), and displaying (in a human-perceptible manner) at least one of the following: temperature and / or measured humidity and / or pressure and / or airflow parameters and / or other relevant information of the exhaled air.

[0057] In some embodiments, the temperature of the collector is measured multiple times during a single exhalation, at a rate of not less than once every 2 seconds in some embodiments, at a rate of not less than once per second in some embodiments, and at a rate of not less than twice per second in some embodiments.

[0058] Various aspects and embodiments of the present invention are described herein in the following description and appended claims. Brief description of the attached diagram

[0059] This document describes some embodiments of the invention with reference to the accompanying drawings. The description, taken in conjunction with the drawings, makes it apparent to those skilled in the art how some embodiments of the invention can be practiced. The drawings are for illustrative purposes and do not attempt to show structural details of the embodiments in a more detailed manner than necessary for a basic understanding of the invention. For clarity, some objects depicted in the drawings are not to scale.

[0060] In the attached diagram: Figure 1A and Figure 1B An embodiment of the device according to the teachings herein is schematically depicted in a side cross-sectional view; and Figure 2A and Figure 2B Another embodiment of the device according to the teachings herein is schematically depicted in a side cross-sectional view; and Figure 3 The temperature of the collector is schematically depicted at different stages of a single exhalation. Description of some embodiments of the invention

[0061] In some embodiments, the present invention relates to a method and apparatus for measuring the temperature of exhaled gas.

[0062] The principles, uses, and implementations of this invention can be better understood by referring to the accompanying description and drawings. After carefully reading the description and drawings provided herein, those skilled in the art will be able to implement the teachings of this invention without excessive effort or experimentation. In the drawings, similar reference numerals always refer to similar parts.

[0063] Before explaining at least one embodiment of the invention in detail, it should be understood that the invention is not limited in its application to the details of the construction and arrangement of the components and / or methods set forth herein. The invention can have other embodiments or be practiced or implemented in various ways. The wording and terminology used herein are for descriptive purposes and should not be considered limiting.

[0064] As stated in the introduction, methods and apparatus for measuring the temperature of exhaled gases would be useful. The teachings of this article provide methods and apparatus comprising a conduit defining an air passage in which a collector is located.

[0065] The subject, such as a person, exhales air from the respiratory system through the mouth into the airway via the mouthpiece of the catheter.

[0066] Exhaled air flows through the air passage and heats or cools the collector based on the temperature difference between the exhaled air and the collector.

[0067] The temperature of the solar collector is measured. By inference, the measured temperature of the solar collector is considered to be the same as the temperature of the exhaled air or the temperature of a portion of the exhaled air associated with a certain phase of exhalation, or to indicate the temperature of the exhaled air or the temperature of a portion of the exhaled air associated with a certain phase of exhalation.

[0068] Temperature measured multiple times In some embodiments, the temperature of the collector is measured multiple times with each exhalation. In some such embodiments, the temperature measured at different times during exhalation is correlated with the temperature of different parts of the respiratory system.

[0069] In some such embodiments, the temperature of the collector is measured at least once every two seconds, at least once per second, and even at least twice per second.

[0070] In some alternative embodiments, different collector temperatures are measured during multiple exhalations, wherein each exhalation is divided into multiple phases, and the temperature is measured separately for each phase of each exhalation (e.g., T1(a), T1(b), T1(c), T1(d), T1(e); T2(a), T2(b), T2(c), T2(d), T2(e); T3(a), T3(b), T3(c), T3(d), T3(e); where T1(a) is the temperature measured in phase (a) of the first exhalation, T2(a) is the temperature measured in the same phase (a) of the second exhalation, T3(b) is the temperature measured in the next phase (b) of the third exhalation, and so on). In this way, for each phase (a), (b), ... (i) of the exhalation, an average temperature or a trimmed mean can be measured, which can be better correlated with the temperature of different parts of the respiratory system. In some preferred embodiments, the start of each exhalation is taken as the start time t0, and each phase is defined as having a start time and an end time associated with the start time t0. For example, in the example above, for each exhalation, phase (a) can be defined as t0+0 seconds to t0+0.5 seconds, phase (b) as t0+0.5 seconds to t0+1.0 seconds, phase (c) as t0+1.0 seconds to t0+1.5 seconds, phase (d) as t0+1.5 seconds to t0+2.0 seconds, and phase (e) as t0+2.0 seconds to t0+2.5 seconds.

[0071] As an example, in Figure 3 In this study, the phases (a), (b), (c), (d), and (e) of three consecutive exhalations (exhalation 1, exhalation 2, and exhalation 3) and the corresponding temperatures T1(a), T1(b), T1(c), T1(d), T1(e), T2(a)...T3(e) are described. The duration of each of the phases (a), (b),...(i) of the exhalation need not be the same; for example, phase (a) can be defined as t0+0 seconds to t0+0.4 seconds, phase (b) as t0+0.4 seconds to t0+0.9 seconds, phase (c) as t0+0.9 seconds to t0+1.6 seconds, phase (d) as t0+1.6 seconds to t0+2.2 seconds, and phase (e) as t0+2.2 seconds to t0+3.0 seconds.

[0072] In some embodiments, EBT is measured multiple times at each phase of exhalation.

[0073] Those skilled in the art can readily determine the start time of exhalation, the duration of each phase, and the end time based on, for example, the detection of exhaled airflow through the air channel, the detection of temperature changes in the collector (e.g., as measured by a temperature measuring device), and / or the detection of pressure changes in the air channel.

[0074] Replaceable catheter In a preferred embodiment, the device includes a conduit assembly and a body assembly. The conduit assembly includes at least a conduit and a collector (and optionally, other components, such as a temperature sensor (which is part of the temperature measuring device) and / or additional components, such as a humidity sensor and / or a pressure sensor and / or an airflow detector). The body assembly includes other components of the device. In preferred embodiments of this type, the conduit assembly and the body assembly are reversibly separable (e.g., reversibly user-separable) from an engaged state in which the device can be used to a disengaged state, and from a disengaged state to an engaged state. In some such embodiments, the nozzle is a component of the body assembly, but in some preferred embodiments, the nozzle is a component of the conduit assembly.

[0075] In such embodiments, the catheter assembly, including components that are exposed to contact with the subject's fluids (e.g., saliva and exhaled air) during use of the device and thus may be contaminated with pathogens, may be discarded, cleaned, or sterilized, for example, by steam sterilization, while the body assembly, comprising only components that do not substantially contact the subject's fluids, is retained for future use. In some embodiments, the body assembly is configured to allow cleaning and sterilization using a suitable sterilization method (e.g., immersion sterilization).

[0076] In such embodiments, it is preferred that the relatively expensive components of the optional device (such as a display, user interface, processor, wireless transmitter, and / or power source such as a battery) are components of the main assembly. In some preferred embodiments, the conduit assembly is configured to be disposable and includes only relatively inexpensive components.

[0077] Solar collector with wired connection via duct In some embodiments, the collector is physically associated with a duct and is preferably configured for efficient heat exchange with exhaled air in the air passage. In some such embodiments, the collector is in physical contact with a temperature sensor (a component of a temperature measuring device), such as a thermocouple, thermistor, integrated circuit, or other suitable temperature sensor, which provides thermal conduction between the collector and the temperature sensor. The temperature sensor is preferably in wired communication with electronic circuitry (also a component of the temperature measuring device), which determines the temperature of the collector based on information received from the temperature sensor via wired communication.

[0078] In a preferred embodiment of this type, the conduit, the collector, and the temperature sensor are part of the conduit assembly, and the electronic circuitry is part of the main assembly. The conduit assembly and the main assembly can be reversibly separated from a connected state in which there is wired communication between the temperature sensor and the electronic circuitry to a separated state in which there is no wired communication between the temperature sensor and the electronic circuitry.

[0079] Such an embodiment is in Figure 1A and Figure 1B The device 10 is schematically depicted in a side cross-section.

[0080] Device 10 includes a conduit assembly 12, which includes a conduit 14 and a collector 20. The conduit 14 defines an air passage 16 and has an integrally formed nozzle 18 at its proximal end. The collector 20 is disposed within the air passage 16. The collector 20 is physically associated with a temperature sensor 24 (such as a thermistor, thermocouple, or integrated circuit) having leads 22a and 22b passing through the wall of the conduit 14 and connected to electrical contacts 26. In device 10, the collector 20 is a pleated thin copper foil tightly wrapped around the temperature sensor 24.

[0081] Device 10 also includes a main body assembly 28, which includes a body 30 made of plastic and a controller 32 (including a microprocessor on a printed circuit board). The controller 32 is functionally associated with a power supply 34 (a primary or rechargeable battery), a display screen 36, and a temperature measuring electronic circuit 38 having two conductive circuit leads 40a and 40b electrically connected to electrical contacts 42.

[0082] exist Figure 1A In the diagram, device 10 is shown in a disconnected state, where there is no wired communication between temperature sensor 24 and temperature measurement circuit 38.

[0083] exist Figure 1B In this embodiment, device 10 is depicted in a connected state, wherein, among other things, contact 26 is in electrical contact with contact 42, thereby establishing wired communication between temperature sensor 24 and temperature measurement circuit 38.

[0084] When device 10 is in Figure 1B In the connected state, a person exhales air from their mouth through the mouthpiece 18 into the air passage 16, preferably while simultaneously surrounding the mouthpiece 18 with their lips. During exhalation, the collector 20 heats or cools to approach and even reach the temperature of the exhaled air passing through the air passage 16. The temperature of the temperature sensor 24 (which is thermally connected to the collector 20) also changes. The controller 32 determines the temperature of the collector 20 via temperature measuring electronics 38 and infers the temperature of the exhaled air based on data received from the temperature sensor 24. The measured temperature is displayed on the display screen 36 and / or transmitted to a remote device via the controller 32.

[0085] Solar collector with non-contact thermometer In some embodiments, the temperature measuring device includes a non-contact thermometer having an IR transparent detection window positioned to receive IR radiation emitted from the location of the solar collector in the air channel as exhaled air passes through it. As the exhaled air passes through the air channel, the solar collector heats or cools to approach and even reach the temperature of the exhaled air passing through the air channel. The solar collector emits IR radiation correlated with its temperature, which is received by the non-contact thermometer through the detection window, thereby allowing the temperature of the solar collector to be measured and the temperature of the exhaled air to be determined by inference.

[0086] In a preferred embodiment, the detection window of the non-contact thermometer is located outside the air passage. In some such embodiments, at least a portion of the conduit is transparent to IR radiation, such that IR radiation emitted from the collector passes through the IR-transparent portion of the conduit to be received by the detection window of the non-contact thermometer.

[0087] In a preferred embodiment of this type, the collector and conduit are part of the conduit assembly, and the non-contact thermometer (e.g., Melexis NV, Ypres, Belgium's MLX90614) is a component of the main assembly. The conduit assembly and the main assembly can be reversibly separated from a connected state and a disconnected state, wherein in the connected state, the detection window of the non-contact thermometer is positioned to receive IR radiation emitted from the location of the collector in the air channel as exhaled air passes through the air channel.

[0088] Such an embodiment is in Figure 2A and Figure 2B Device 44 is schematically depicted in a side cross-section.

[0089] Device 44 includes a duct assembly 12, which includes a duct 14 and a collector 20. The duct 14 defines an air passage 16 and has an integrally formed nozzle 18 at its proximal end. The collector 20 is disposed within the air passage 16. In device 44, the collector 20 is a sphere made of thin aluminum foil (e.g., 0.3-0.5 mm thick) physically connected to the duct 14 by a holder 46, which anchors the collector 20 in a fixed position within the air passage 16. A portion of the duct 14 is an IR transparent window 48 (e.g., of PMMA) near the collector 20.

[0090] Device 44 also includes a main body assembly 28, which includes a main body 30 and a controller 32 (including a microprocessor on a printed circuit board). The controller 32 is functionally associated with a power supply 34 (a primary or rechargeable battery), a display screen 36, and a non-contact thermometer 50 (with a detection window 52). The main body 30 is made of opaque polycarbonate, completely blocking the passage of light (especially IR light).

[0091] exist Figure 2A In the text, device 44 is described as being in a separated state.

[0092] exist Figure 2B In the text, device 44 is described as being in a connected state, wherein Among other things The detection window 52 of the non-contact thermometer 50 is positioned to receive IR radiation emitted from the collector 20 and passing through the IR transparent window 48. The body 30 prevents any ambient infrared radiation from reaching the collector 20.

[0093] When device 44 is in Figure 2BIn the connected state shown, a person exhales air from their mouth through the mouthpiece 18 into the air passage 16. During exhalation, the collector 20 heats or cools the air to approach or even reach the temperature of the exhaled air passing through the air passage 16. The temperature of the collector 20, and therefore the temperature of the exhaled air, is determined by the controller 32 and displayed on the display screen 36 with reference to data received from the non-contact thermometer 50.

[0094] In device 44, conduit 14 includes an IR-transparent window 48. This IR-transparent window is smaller than the entire conduit. In some alternative embodiments, substantially the entire conduit (e.g., at least about 70%, at least about 80%, and even at least about 90% of the conduit) is transparent to IR radiation, for example, the conduit is made of PMMA.

[0095] In the device 44, the collector 20 is fixedly mounted within the air passage 16 by means of the bracket 46. In some embodiments, the collector 20 may be movable within the air passage 16, but when air is exhaled into the air passage 16 through the mouthpiece 18, the collector 20 is positioned within the air passage 16 to allow IR radiation from the collector 20 to enter the detection window 52 of the non-contact thermometer 50.

[0096] Preferably, the collector has a relatively low heat capacity, such that the temperature of the collector surface changes relatively rapidly during interaction with exhaled air. In some embodiments, the collector has a relatively low mass and / or has at least a portion made of a material with a low volumetric heat capacity. In some embodiments, at least a portion of the collector is made of a material with a molar heat capacity of no more than about 30 J / (mol K) and even no more than about 15 J / (mol K). In some embodiments, at least about 30% by weight of the collector is made of a material with a molar heat capacity of no more than about 30 J / (mol K) and even no more than about 15 J / (mol K). In some embodiments, at least about 50% by weight of the collector is made of a material with a molar heat capacity of no more than about 30 J / (mol K) and even no more than about 15 J / (mol K).

[0097] Preferably, the collector has a relatively high thermal conductivity, such that the temperature of the entire collector surface will be relatively quickly equalized during interaction with exhaled air. In some embodiments, at least a portion of the collector is made of a material having a thermal conductivity of not less than about 20 W / m K and even not less than about 100 W / m K and even not less than about 300 W / m K. In some embodiments, at least about 30% by weight of the collector is made of a material having a thermal conductivity of not less than about 20 W / m K and even not less than about 100 W / m K and even not less than about 300 W / m K. In some embodiments, at least about 50% by weight of the collector is made of a material having a thermal conductivity of not less than about 20 W / m K and even not less than about 100 W / m K and even not less than about 300 W / m K.

[0098] Preferably, the collector has a relatively high emissivity, particularly in the IR portion of the spectrum. In some embodiments, at least a portion of the collector is made of a material having an emissivity of not less than about 0.05 and even not less than about 0.1. In some embodiments, at least about 30% by weight of the collector is made of a material having an emissivity of not less than about 0.05 and even not less than about 0.1. In some embodiments, at least about 50% by weight of the collector is made of a material having an emissivity of not less than about 0.05 and even not less than about 0.1.

[0099] Materials suitable for solar collectors include, but are not limited to:

[0100] In device 44, collector 20 is a spherical element made of thin aluminum foil (e.g., 0.3 mm to 0.5 mm thick). In some embodiments, the collector has a three-dimensional shape, such as spherical, teardrop-shaped, bullet-shaped, olive-shaped, and cubic. In a preferred embodiment, this three-dimensional shape is hollow. The advantage of a hollow three-dimensional shape is that the heat capacity of the collector is reduced, but the surface area interacting with the exhaled air in the air passage is relatively large.

[0101] In some embodiments, the collector is hollow, having an empty internal volume. In some such embodiments, the collector wall thickness is no more than about 1 mm, no more than about 0.5 mm, and even no more than about 0.3 mm. In some such embodiments, the collector wall thickness is not less than about 0.05 mm, and even not less than about 0.01 mm. In preferred embodiments of this type, holes are present in the surface of the collector, allowing exhaled air to enter the internal volume of the collector and heat the collector from the inside.

[0102] In some embodiments, the collector is hollow, and the ribs of the thermally conductive material are within the internal volume of the collector, thereby allowing rapid heat transfer throughout the collector, which allows for more rapid temperature equalization across the entire surface of the collector. For example, in some such embodiments, the collector is, for instance, a hollow aluminum sphere with aluminum chords spanning the internal volume, fabricated by 3D printing.

[0103] In some alternative embodiments, the collector at least partially comprises, and in some embodiments is, a sheet (e.g., a two-dimensional shape, such as a plate, plate, foil, or film), for example, in some embodiments, the collector is a foil sheet. In some such embodiments, the collector is no more than about 2 mm thick, no more than 1 mm thick, no more than about 0.5 mm thick, and even no more than about 0.3 mm thick. In some such embodiments, the collector is not less than about 0.1 mm thick, not less than about 0.05 mm thick, and even not less than about 0.01 mm thick.

[0104] In some embodiments, the collector is aerodynamically shaped to minimize drag and reduce the formation of turbulence in the exhaled air flowing in the air passage. Alternatively, in some embodiments, the collector has surfaces that increase the formation of turbulence near the surface, thereby allowing an increase in the volume of air interacting with the collector; for example, the collector has a rough surface including fins, protrusions, spikes, etc.

[0105] In some embodiments, the collector at least partially includes, and in some embodiments is, wire (e.g., aluminum, copper, gold, silver, and alloys thereof). In some preferred embodiments of this type, the wire is shaped (e.g., folded, bent, wrinkled, braided, wound, or wound in one or more ways) into a 3D shape, most preferably into a hollow 3D shape. As used herein, “wire” means any elongated component whose length dimension is at least 10 times its axial dimension, and includes components such as strips, strands, filaments, wires, lines, rods, ropes, etc. In some embodiments of this type, the wire has a radial dimension (e.g., diameter) of not more than about 2 mm, not more than about 1 mm, not more than about 0.6 mm, and even not more than about 0.3 mm. Additionally or alternatively, in some embodiments, the wire has a radial dimension of not less than about 0.05 mm and even not less than about 0.01 mm.

[0106] In some embodiments, the collector includes a coating (in some such embodiments, not less than about 1 micrometer and even not less than about 5 micrometers; additionally or alternatively, not more than about 500 micrometers, for example 200-300 micrometers), the coating material having a high thermal conductivity, for example, not less than about 100 W / m K (e.g., graphene, graphite, diamond, SiC, gold, copper, silver and alloys thereof), and / or the coating having a low volumetric heat capacity material supported by a material core having low thermal conductivity and / or high volumetric heat capacity. Such a collector can be manufactured by any suitable method, such as electroplating or deposition.

[0107] In devices 10 and 44, the nozzle 18 is integrally formed with the catheter 14. In some embodiments, the nozzle is a component separate from and attached to the catheter. In some such embodiments, the nozzle is a component of the main body assembly. Preferably, the nozzle is a component of the catheter assembly.

[0108] The inner wall of the duct (lining the air passage) is made of any suitable material having any suitable properties. In a preferred embodiment, the inner wall of the duct (particularly near the collector) has a low thermal conductivity and / or is suitably shaped and / or has a suitable surface to facilitate laminar airflow near the wall, such that there is little (preferably no) heat exchange between the wall of the duct and the exhaled air flowing through it. In some embodiments, the inner duct wall (particularly near the collector) has a thermal conductivity of no more than about 0.5 W / (m K). In some embodiments, the inner duct wall near the collector comprises at least 50% by weight of a material selected from the group consisting of plastics, PVC (polyvinyl chloride), polycarbonate, PP (polypropylene), PET (polyethylene terephthalate), PE (polyethylene), polyamide (nylon), and PTFE (polytetrafluoroethylene).

[0109] In some embodiments of the device, such as variations of device 10 or 44, controller 32 includes additional components or is functionally associated with additional components, such as computer memory, wireless transmitters or transceivers, on / off switches and other peripheral hardware, as well as software / firmware configured to operate device 10 or 44.

[0110] In some embodiments, the device includes a humidity and / or pressure sensor configured to measure the humidity and / or pressure of exhaled air flowing through the duct, and preferably configured to provide the measured humidity and / or pressure to a controller. In some such embodiments, the output of the humidity and / or pressure sensor (preferably by the controller) is used to adjust the calculation of the temperature of the collector and / or the exhaled air. Specifically, the output of the humidity sensor is used (e.g., by the controller) to correct the temperature of the collector, as measured by a temperature sensor, to account for the humidity of the exhaled air.

[0111] In some embodiments, the device is configured such that the inner wall of the conduit is insulated from ambient temperature, such as ambient air temperature, or the heat of the hand of a user holding the device.

[0112] In some embodiments, the device is configured to reduce, and more preferably prevent, the intake of air through the air passage. Specifically, the device is configured to prevent air from flowing back through the mouthpiece from the air passage (e.g., caused by a person inhaling through the mouthpiece while it is held in their mouth). In some such embodiments, the conduit includes a one-way valve. This one-way valve can be used to prevent air from flowing back through the mouthpiece from the air passage. According to embodiments, the one-way valve is located at the distal end of the conduit, in the mouthpiece, or somewhere along the air passage. In a preferred embodiment, the one-way valve is located downstream of the collector to reduce and even prevent ambient air from entering the air passage and affecting the temperature of the collector.

[0113] In devices 10 and 44, controller 32 receives data related to the temperature of collector 20, calculates the temperature on a meaningful scale (e.g., °C or °F), and displays the temperature on display screen 36. In some alternative embodiments, the temperature of collector 20 is calculated based on data from a remote location of the device, for example, the data is transmitted to a remote processor, such as a smartphone processor, which calculates the temperature on a meaningful scale. Additionally or alternatively, in some alternative embodiments, the calculated temperature is displayed at a remote location of the device, for example, on a smartphone display screen. Additionally or alternatively, in some embodiments, the calculated temperature is not displayed; instead, the data related to the collector's temperature is used in a different manner.

[0114] In some embodiments, in addition to measuring the instantaneous temperature of the collector, the controller is configured to implement additional features such as: calculating the average, trimmed mean, maximum, and minimum temperature values ​​for a predetermined or variable (user-controlled) number of breaths or time period (e.g., 10 breaths or 30 seconds); a graphical representation of temperature changes over time; and self-calibration. Among other things Utilizes a built-in NIST traceable high-precision digital temperature sensor (e.g., the SHT35-DIS from Sensirion, Switzerland).

[0115] Self-calibration Calibrating a non-contact IR thermometer is not an easy task and usually requires specialized calibration equipment, such as a blackbody cavity, a precision reference thermometer, or a hygrometer. Such calibration equipment is quite expensive and requires specialized skills to operate correctly.

[0116] In some embodiments, device 44 includes a non-contact IR thermometer configured to perform self-calibration. If the device is not used for a period of time, such as several hours, the temperature of all components within the device, including the collector, will be equal to the ambient temperature. Given that modern electronic components can operate in low-power ranges, the effect of the electronic circuitry on the temperature of internal components during self-calibration is negligible. To ensure better temperature stability, the device can be kept in a thermally insulated container. The temperature of the collector is measured by the device's IR thermometer and compared with a temperature measured by a built-in high-precision digital temperature sensor (e.g., the SHT35-DIS from Sensirion, Switzerland). The results of the two measurements should be identical, and if they differ, the difference is used to calibrate the IR thermometer. For even more precise calibration, the device should be held in a thermostat for a certain period of time at various ambient temperatures (e.g., 15°C, 20°C, 25°C, 30°C, and 35°C) before performing self-calibration. The calibration value for each temperature measurement is stored in memory and used during EBT measurements.

[0117] In some embodiments, the humidity of the air is additionally measured using a built-in humidity sensor and further used to calibrate a non-contact IR thermometer.

[0118] In some embodiments, device 10 includes a contact thermometer configured to perform a self-calibration process similar to that described for device 44.

[0119] In devices 10 and 44, the power source 34 is a battery (e.g., a primary cell or a rechargeable battery). Embodiments of the device use any suitable power source, such as a supercapacitor or a solar cell.

[0120] Unless otherwise defined, 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 pertains. In case of conflict, the specification (including definitions) takes precedence.

[0121] As used herein, the terms “comprising,” “including,” “having,” and their grammatical variations shall be regarded as designating the stated feature, whole, step, or component, but do not preclude the addition of one or more additional features, wholes, steps, components, or groups thereof. As used herein, unless the context clearly indicates otherwise, the indefinite articles “a” and “an” mean “at least one” or “one or more.”

[0122] As used herein, when the term "about" precedes a numerical value, it is intended to indicate + / - 10%. As used herein, the term "A and / or B" means a selection from the group consisting of (A), (B), or (A and B). As used herein, the term "at least one of A, B, and C" means a selection from the group consisting of (A), (B), (C), (A and B), (A and C), (B and C), or (A and B and C).

[0123] It should be understood that certain features of the invention described in the context of a single embodiment for clarity may also be provided in combination in a single embodiment. Conversely, various features of the invention described in the context of a single embodiment for brevity may also be provided individually or in any suitable sub-combination, or are adapted to be provided in any other described embodiments of the invention. Certain features described in the context of various embodiments are not considered essential features of those embodiments unless the embodiment does not function without those elements.

[0124] Although the invention has been described in conjunction with specific embodiments thereof, it will be apparent to those skilled in the art that many alternatives, modifications, and variations will be apparent. Therefore, the invention is intended to cover all such alternatives, modifications, and variations falling within the scope of the appended claims.

[0125] Any reference or identification of references in this application shall not be construed as an admission that such references may be used as prior art of the present invention.

[0126] The chapter titles used in this document are for ease of understanding of the instructions and should not be construed as necessary limitations.

Claims

1. A device adapted to determine the temperature of exhaled breath (EBT), comprising: a conduit defining an air passage; a heat collector within the air passage; a mouthpiece functionally associated with the conduit and configured so that when a person exhales air through the mouth, the mouthpiece directs the exhaled air into the air passage so that the exhaled air can exchange heat with the heat collector; a temperature determiner configured to determine the temperature of the heat collector at least once during exhalation through the mouthpiece; and a controller comprising a computer processor and a memory for receiving the temperature determined by the temperature determiner and for subsequently calculating an indicative temperature indicative of the temperature of the exhaled air, the calculation being based on the temperature of the heat collector determined by the temperature determiner.

2. The device of claim 1, wherein the temperature determiner and the controller are configured to determine the temperature of the heat collector multiple times during a single exhalation through the mouthpiece. The temperature determiner and the controller are configured to determine the temperature of the heat collector for a predefined or variable number of phases of a single exhalation.

3. The apparatus of claim 2, wherein, 4. The device of any one of claims 1 to 3, wherein the temperature determiner is configured to determine the temperature of the heat collector at least once every second.

5. The device of any one of claims 1 to 4, comprising: a conduit assembly comprising at least the conduit and the heat collector; and a body assembly comprising the other components of the device, wherein the conduit assembly and the body assembly are reversibly separable from a coupled state, in which the device can be used to determine EBT, to a separated state. The mouthpiece is a component of the body assembly. The mouthpiece is a component of the conduit assembly.

6. The apparatus of claim 5, wherein, The mouthpiece is integrally formed with the conduit.

7. The apparatus of claim 5, wherein, The heat collector is physically connected to the conduit.

8. The apparatus of any one of claims 1-7, wherein, The heat collector is in physical contact with a temperature sensor, the temperature sensor being a component of the temperature determiner, the physical contact providing thermal conduction between the heat collector and the temperature sensor.

9. The apparatus of any one of claims 1-8, wherein, The temperature sensor comprises a component selected from the group consisting of a thermocouple, a thermistor, and an integrated circuit.

10. The apparatus of any one of claims 1 to 8, wherein, The temperature sensor is in wired electrical communication with an electronic circuit, the electronic circuit being a component of the temperature determiner, the temperature determiner determining the temperature of the heat collector from information received from the temperature sensor through the wired communication.

11. The apparatus of claim 10, wherein, 13. The device of claim 12, comprising:

12. The apparatus of any one of claims 10-11, wherein, a conduit assembly comprising the conduit, the heat collector, and the temperature sensor; and a body assembly comprising the electronic circuit, wherein the conduit assembly and the body assembly are reversibly separable from a coupled state, in which there is wired communication between the temperature sensor and the electronic circuit enabling the device to be used to determine EBT, to a separated state, in which there is no wired communication between the temperature sensor and the electronic circuit. ​ ​ ​ 14. The apparatus of any one of claims 1 to 8, wherein the temperature determiner comprises a non-contact thermometer having a detection window positioned to receive IR radiation emitted from a location in the air channel where the heat collector is located when exhaled air passes through the air channel.

15. The apparatus of claim 14, wherein, The detection window of the non-contact thermometer is located outside of the air channel.

16. The apparatus of claim 15, wherein, At least a portion of the conduit is transparent to IR radiation such that IR radiation emitted from the heat collector passes through the IR transparent portion of the conduit to be received by the detection window of the non-contact thermometer.

17. The apparatus of any one of claims 14 to 16, comprising: a conduit assembly comprising the conduit and the heat collector; and a body assembly comprising the non-contact thermometer, wherein the conduit assembly and the body assembly are reversibly separable from a coupled state in which the detection window of the non-contact thermometer is positioned to receive IR radiation emitted from a location in the air channel where the heat collector is located when exhaled air passes through the air channel, to a decoupled state, such that the apparatus can be used to determine EBT.

18. The apparatus of any one of claims 14-17, wherein, The heat collector is fixedly mounted within the air channel.

19. The apparatus of any one of claims 14-17, wherein, The heat collector is movable within the air channel, but is located in the air channel in a position that allows IR radiation from the heat collector to enter the detection window of the non-contact thermometer when air is inhaled through the mouthpiece into the air channel.

20. The apparatus of any one of claims 1 to 19, wherein, An inner wall of the conduit proximate the heat collector has a thermal conductivity of no more than about 0.5 W / (m K).

21. The apparatus of any one of claims 1 to 20, wherein, The heat collector has a three-dimensional shape.

22. The apparatus of claim 21, wherein, The heat collector is hollow, having an internal volume.

23. The apparatus of claim 22, comprising at least one hole in a surface of the heat collector that allows exhaled air to enter the internal volume of the heat collector.

24. The apparatus of any one of claims 21-23, wherein, A rib of thermally conductive material is within the internal volume of the heat collector, allowing for rapid heat transfer throughout the heat collector.

25. The apparatus of any one of claims 1 to 24, wherein, The heat collector comprises a sheet.

26. The apparatus of any one of claims 1 to 25, wherein, The heat collector comprises a wire.

27. The apparatus of claim 26, wherein, The wire is shaped into a 3D shape.

28. The apparatus of any one of claims 1 to 27, further comprising a humidity sensor configured to determine a humidity of exhaled air flowing through the conduit and to provide the determined humidity to the controller.

29. The apparatus of claim 28, wherein, The controller is configured to use the received humidity of the exhaled air to account for the humidity of the exhaled air.

30. The apparatus of any one of claims 1 to 29, further comprising a pressure sensor configured to determine a pressure of exhaled air flowing through the conduit and to provide the determined pressure to the controller.

31. The apparatus of any one of claims 1 to 30, further comprising an air flow detector configured to detect an air flow through the conduit and to provide an indication of air flow in the air channel to the controller.

32. The device of any one of claims 1 to 31, configured to prevent backflow of air from the air passage past the heat collector.

33. The device of claim 32, comprising a one-way valve that prevents backflow of air from the air passage past the heat collector.

34. The device of any one of claims 1 to 33, further comprising a transmitter configured to communicate with a remote device, wherein the transmitter is selected from the group consisting of a wired transceiver, an infrared transceiver, a radio frequency transceiver, and a Li-Fi transceiver.

35. The device of any one of claims 1 to 34, further comprising hardware and software / firmware configured to provide self-calibration of temperature measurements.

36. A method for determining exhaled breath temperature (EBT), the method comprising: a. providing a device, the device comprising: a conduit defining an air passage, a heat collector located in the air passage, and a mouthpiece in fluid communication with the air passage; b. during exhalation of air from a subject’s mouth through the mouthpiece and into the air passage, exhaled air during its entry into the air passage exchanges heat with the heat collector, the temperature of the heat collector is determined at least once during the exhalation; and c. calculating an indicative temperature indicative of the temperature of the exhaled air, the calculation based on the temperature of the heat collector determined by the temperature determiner.

37. The method of claim 36, wherein, The indicative temperature is corrected for other factors, for example taking into account the humidity of the exhaled air, and / or modified by a correction factor to account for known and / or expected errors.

38. The method of claim 37, wherein, The temperature of the heat collector is determined multiple times during a single said exhalation.

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