Abstract: A system is provided that includes a portable measurement device for measuring acetone in a breath sample of a user. The measurement device comprises a housing, a user-direct breath input device for engaging in direct fluid communication with a respiratory tract of the user and receiving the breath sample from the respiratory tract, a flow path disposed within the housing, a nanoparticle-based sensor disposed in the housing in fluid communication with the flow path and at an intermediate location between the upstream end and the downstream end, and a flow control device disposed in the housing and in the flow path between the upstream end and the nanoparticle-based sensor that prevents flow of the breath sample in an upstream direction opposite the downstream direction.

Abstract: Various devices are disclosed for measuring the concentration of an analyte, such as acetone, in a breath sample. The disclosed devices include a disposable cartridge containing a reactive material that extracts the analyte from a breath sample passed through the cartridge. In some embodiments, the cartridge contains a solid, porous structure (such as a disk, bowl or puck) that contains the reactive material. To induce a chemical reaction for measuring the quantity of the extracted analyte, the porous structure may be brought into contact with a sponge or pad that dispenses developer solution to the porous structure. Also disclosed are devices for routing a breath sample through the cartridge during exhalation, and for analyzing a reaction in the cartridge to measure a concentration of the analyte.

Abstract: An apparatus and associated method are provided for sensing an analyte, such as acetone, in breath. The apparatus includes a sorbent material that extracts the analyte from a dehumidified breath sample, and a nanoparticle-based sensor. The apparatus produces first and second gas streams that flow over the nanoparticle-based sensor. The first gas stream is used to generate a baseline signal, and the second gas stream is used to carry the extracted analyte from the sorbent material to the nanoparticle-based sensor. Various additional designs of analyte sensing devices are also disclosed.

Abstract: A ketone measurement and analysis system provides various features for enabling health program participants to interpret their ketone measurements, such as breath acetone measurements. One such feature breaks down ketone measurements into causal components. For example, the system may generate and display an estimate of how much of a participant's ketone measurement is attributable to stored fat metabolism versus consumption of a “confounding substance” such as dietary fat and/or exogenous ketones. The system may also estimate the contributions of specific confounding substances, and/or the contributions of other factors or events (such as exercise, interrupted sleep, a missed medication, etc.) that affect ketone levels. Another feature involves the generation and display of target ketone levels that are personalized for the participants. The system may generate the measurement breakdowns and target ketone levels by applying data mining algorithms to aggregated data of many program participants.

Abstract: A portable system is provided for measuring a ketone, such as an acetone, in the breath or other bodily fluid of a user. The system includes a portable measurement device that analyzes fluid samples and generates corresponding ketone measurements. The portable measurement device communicates with an application which runs on a smartphone or other mobile device of the user. The application tracks, and generates graphs of, the ketone measurements, and may include various features for facilitating the analysis of the measurements.

Abstract: Methods and devices are provided for analyzing acetone in breath. One such method comprises disposing a reactant in a reaction zone within the breath analysis device, wherein the reactant comprises a primary amine disposed on a surface, and wherein the reaction zone has an optical characteristic that is at a reference level. It also comprises pre-storing a liquid nitroprusside solution within the breath analysis device separately from the reactant. The method further comprises using the breath analysis device to cause the breath to contact the reactant in the reaction zone so that the acetone in the breath reacts with the reactant to form a reaction product and, after the reaction product has been formed, using the breath analysis device to cause the nitroprusside solution to contact and react with the reaction product and to facilitate a change in the optical characteristic of the reaction zone relative to the reference level.

Abstract: According to one aspect of the invention, an apparatus is provided for sensing an analyte, such as acetone, in breath. The apparatus includes a conditioning device that dehumidifies a breath sample, a sorbent material that extracts the analyte from the dehumidified breath sample, and a nanoparticle-based sensor. The apparatus produces first and second gas streams that flow over the nanoparticle-based sensor. The first gas stream is used to generate a baseline signal, and the second gas stream is used to carry the extracted analyte from the sorbent material to the nanoparticle-based sensor. Various additional designs of analyte sensing devices are also disclosed.

Abstract: A wearable breath analysis device is disclosed that may be worn, for example, around the neck or wrist of a user. The wearable device may be a stand-along device (in which case it may include a display that provides a user interface), or may operate in conjunction with a smartphone or other command device. The wearable device may include auditory and/or vibratory notice and communications features or capabilities, for example, such as a reminder or notice to conduct a breath analyte measurement, instructions to the user in the course of conducting the measurement, and notice of the breath analyte measurement results. The auditory or vibratory notice may be provided at the wearable, and/or at the command device where a command device is used. Related methods also are provided.

Abstract: A portable system is provided for measuring a ketone, such as an acetone, in the breath or other bodily fluid of a user. The system includes a portable measurement device that analyzes fluid samples and generates corresponding ketone measurements. The portable measurement device communicates with an application which runs on a smartphone or other mobile device of the user. The application tracks, and generates graphs of, the ketone measurements, and may include various features for facilitating the analysis of the measurements.

Abstract: A method is provided for sensing ammonia in a breath sample. The method comprises conditioning the breath sample so that the conditioned breath sample has a relative humidity greater than a relative humidity corresponding to a first inflection point of a downwardly concave lowest ammonia iso-concentration curve. It also comprises contacting the conditioned breath sample with an interactant that interacts with the ammonia in the conditioned breath sample, wherein the interaction causes a change in an optical characteristic in relation to the amount of the ammonia in the breath sample. It further comprises using the change in the optical characteristic to sense the ammonia in the breath sample. Related apparatuses are also provided.

Abstract: A breath capture device for determining the concentration of acetone in a breath sample from a user. In some embodiments, the device includes a controller programmed to use stored data to control flow of a breath sample into an analysis chamber as the user exhales into a port. In other embodiments, the device includes a switch responsive to an action by the user that is operable between a first orientation in which breath entering the port preferentially travels through a second flow path and a second orientation in which breath entering the port preferentially travels through a first flow path. In still other embodiments, the device includes a flow regulator both responsive to user action and operable from a first position in which breath entering a port preferentially travels through a second flow path to a second position in which breath entering the port preferentially travels through a first flow path.

Abstract: Some embodiments of the invention provide a mouthpiece for use with an electronic analyzer for breath analyte detection in an individual. The mouthpiece includes a biosensor and a hydration system. The biosensor includes a chemically active area where a chemical reaction takes place and the hydration system delivers a liquid to the chemically active area of the biosensor to at least one of enhance, enable, and facilitate the chemical reaction. The mouthpiece further includes hardware to transmit breath analyte data.

Abstract: A system is disclosed that uses profiles of users, including monitored ketone levels of the users, to assess effectiveness levels of health programs (such as weight loss programs) assigned to the users, and to select health program modifications for the users. The system may use a machine learning (artificial intelligence) algorithm to adaptively learn how to classify users and to select messaging and behavioral modifications for the users. For example, in some embodiments the system classifies the users and provides associated health program recommendations using a computer model trained with expert-classified user data records. As another example, a set of rules may be used to generate the health program recommendations and related messaging, and the set of rules may automatically be modified over time based on feedback data reflective of health program effectiveness levels produced by such rules.