Abstract: The invention includes sweat sensing devices to measure volumetric sweat rate that use alternating current interrogation of electrodes, and embodiments that have a reusable component and a disposable component. The disclosure further includes a method for detecting an air bubble within a volumetric sweat rate device. The disclosure also includes methods, systems, and non-transitory computer-readable storage medium claims for using a device configured to perform periodic volumetric sweat rate measurements to inform estimates of total body water loss, to aid in the avoidance of heat stress or dehydration, and to facilitate comparison of environmental influences on heat stress or dehydration.

Abstract: Embodiments of the disclosed invention provide devices and methods to incorporate suspension-based, i.e., hydrogel-based and thixotropic compound-based, ion-selective electrodes and reference electrodes into a wearable sweat sensing device. Embodiments of this device are configured to monitor sweat electrolyte concentrations, trends, and ratios under demanding use conditions. The accompanying method includes use of the disclosed device to track fluid and electrolyte gain and loss in order to produce an electrolyte estimate, such as a sweat electrolyte concentration, a sweat electrolyte concentration trend, a sweat rate, or a concentration ratio between a plurality of electrolytes.

Abstract: The disclosed invention provides a fluid sensing device and method capable of collecting a fluid sample, concentrating the sample with respect to one or more target analytes, and measuring the target analyte(s) in the concentrated sample. The invention is also capable of determining the change in molarity of the fluid sample with respect to the target analyte(s), as the sample is concentrated by the device. The invention further includes a method for using a fluid sensing device to concentrate a fluid sample with respect to one or more target analytes. The disclosed method further includes the ability to correlate the measured target analyte concentration to a physiological condition of a device wearer, or of a fluid source.

Abstract: The disclosed invention provides a fluid sensing device and method capable of collecting a fluid sample, concentrating the sample with respect to one or more target analytes, and measuring the target analyte(s) in the concentrated sample. The invention is also capable of determining the change in molarity of the fluid sample with respect to the target analyte(s), as the sample is concentrated by the device. The invention further includes a method for using a fluid sensing device to concentrate a fluid sample with respect to one or more target analytes. The disclosed method further includes the ability to correlate the measured target analyte concentration to a physiological condition of a device wearer, or of a fluid source.

Abstract: Embodiments of the disclosed invention provide devices and methods for buffering fluid samples to enable accurate concentration measurements of analytes by salinity-sensitive or pH-sensitive sensors. The buffering capabilities of the device include the ability to control the salinity and pH of a fluid sample, specifically, through the management of solutes such as salts, H+, other ions, and other solutes, that are found in sweat, biofluids, or other fluids. The purpose of such control is to enhance particular fluid sensing device applications by improving detectability of the targeted analyte, or improving performance of analyte sensors. Some embodiments also include components to enable sample concentration to enhance the measurement of low-concentration solutes found in the fluid.

Abstract: The disclosed invention includes sweat sensing devices configured to periodically measure sweat conductivity and galvanic skin response, devices to measure volumetric sweat flow rate, and devices that combine the three functions. The disclosure further includes methods for using a device configured to perform periodic sweat conductivity measurements, galvanic skin response measurements, and volumetric sweat rate measurements so that each sensor modality informs composite estimates of sweat onset, sweat cessation, sweat ion concentration, and sweat rate. The method uses those measurements to inform other sweat sensing device functions, such as determining the existence of a physiological condition, or performing measurements of concentrations, ratios, and trends of sweat analytes.

Abstract: The disclosed invention provides a modular biofluid sensing device configured to be worn on an individual's skin. The device includes at least one primary module, at least one sensing module, and at least one specialized module. The various subsystems, components, and materials making up a biofluid sensing device are arranged for modular distribution and assembly according to a number of different organizational criteria. These criteria include distributing components into modules based on the requirements of a biofluid sensing device application, manufacturing considerations, component cost, and component lifespan.

Abstract: The disclosed invention provides sweat sensing devices with smart sweat stimulation and sensing embodiments: which improve the dependability and predictability of sweat sampling rates; achieve a desired number of sweat sampling events per day while minimizing skin irritation and prolonging device lifespan; and use physical, optical or thermal sweat stimulation to augment or replace chemical sweat stimulation.

Abstract: A production system includes a structure configured to house a light-activated biological pathway. The production system further includes an optical filter attached to the structure. The optical filter is configured to receive light, to reflect a first portion of the received light, and to transmit a second portion of the received light, wherein the first portion has a different wavelength from the second portion. The production system is further configured to position the light-activated biological pathway to receive the second portion of the receive light.