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: 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: 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: 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: 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: 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: 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: Various systems and devices are disclosed for measuring an analyte, such as acetone, in a breath sample of a human subject. In some embodiments, a system is provided that includes a displosable cartridge having a reaction chamber containing an interactant, such as interactant particles. The interactant reacts with an analyte in a breath sample that is passed along a flow path through the reaction chamber. An optical subsystem measures a color change resulting from a reaction in the reaction chamber; this color change is indicative of a concentration of the analyte in the breath sample. In some embodiments, the optical subsystem illuminates the cartridge using multiple LEDs of different colors or wavelengths.

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: 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 method of synthesizing a nucleic acid complementary to a target nucleic acid sequence in a template nucleic acid includes annealing a swarm primer to a target nucleic acid, the swarm primer overlapping an F1 site of the target nucleic acid and extends toward the F2 site of the target nucleic acid. An inner primer may also be annealed to the target nucleic acid to produce a complimentary nucleic acid having a single-strand loop onto which further primers may anneal. A plurality of amplicons may be reproduced, many of which may have further primers annealed thereto to generate more complementary nucleic acids.

Abstract: According to one aspect of the invention, the apparatus comprises a fluid collecting device configured to receive a sample of breath; a conditioning device coupled to the fluid collecting device and configured to receive the sample of breath and condition the sample with respect to at least one of temperature, flow rate, pressure, humidity, and concentration; and a sensing device coupled to the conditioning device and configured to receive the conditioned sample, wherein the sensing device includes a nanoparticle-based sensor and further whereby the analyte interacts with the sensing device to cause a change that is sensed by the sensing device and wherein the change comprises information useful in characterizing the analyte. Preferably, the apparatus is hand-held and characterizing the analyte is useful for health monitoring.

Abstract: A method of determining the concentration of an analyte of interest in breath. The method includes obtaining a disposable cartridge comprising a reaction chamber, a liquid chamber, and a window to permit determination of a color intensity in the reaction chamber, directing a volume of breath into the cartridge, and initiating a sequence whereby liquid is released from the liquid container into the reaction chamber to cause a reaction which produces a change in the intensity of a color viewable through the window. The intensity of the color corresponds to the concentration of the analyte of interest. The reaction progresses through a kinetic phase and eventually reaches equilibrium. The sequence additionally includes measuring the intensity of the color at a point in the kinetic phase, to determine the concentration of the analyte of interest in breath.

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, the apparatus comprises a fluid collecting device configured to receive a sample of breath; a conditioning device coupled to the fluid collecting device and configured to receive the sample of breath and condition the sample with respect to at least one of temperature, flow rate, pressure, humidity, and concentration; and a sensing device coupled to the conditioning device and configured to receive the conditioned sample, wherein the sensing device includes a nanoparticle-based sensor and further whereby the analyte interacts with the sensing device to cause a change that is sensed by the sensing device and wherein the change comprises information useful in characterizing the analyte. Preferably, the apparatus is hand-held and characterizing the analyte is useful for health monitoring.

Abstract: A method for extending an effective working range of an analyzer for measuring an analyte in a breath sample. The method includes initiating a reaction in the analyzer that produces an optically discernable reaction product having an optical property that is indicative of a concentration of the analyte in the breath sample, taking a first reading of the optical property at a first time, and comparing the first reading to a reference. If the comparison yields a first state, the method includes determining the concentration using the first reading. If it yields a second state different from the first state, the method includes taking a second reading of the optical property at a second time, and determining the concentration of the analyte using the second reading. Other methods are provided as well.

Abstract: A method of synthesizing a nucleic acid complementary to a target nucleic acid sequence in a template nucleic acid includes annealing a swarm primer to a target nucleic acid, the swarm primer overlapping an F1 site of the target nucleic acid and extends toward the F2 site of the target nucleic acid. An inner primer may also be annealed to the target nucleic acid to produce a complimentary nucleic acid having a single-strand loop onto which further primers may anneal. A plurality of amplicons may be reproduced, many of which may have further primers annealed thereto to generate more complementary nucleic acids.

Abstract: A method for extending an effective working range of an analyzer for measuring an analyte in a breath sample. The method includes initiating a reaction in the analyzer that produces an optically discernable reaction product having an optical property that is indicative of a concentration of the analyte in the breath sample, taking a first reading of the optical property at a first time, and comparing the first reading to a reference. If the comparison yields a first state, the method includes determining the concentration using the first reading. If it yields a second state different from the first state, the method includes taking a second reading of the optical property at a second time, and determining the concentration of the analyte using the second reading. Other methods are provided as well.

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.