The present invention relates to an apparatus (10) apparatus for the detection of carbon dioxide. It is described to place (210) a part of a housing in contact with a skin area of a patient. the part of the housing and a gas measuring chamber within the housing are configured such that gases diffusing through the skin area of the patient enter the gas measuring chamber. radiation is emitted (220) from a radiation source within the housing, wherein at least some of the radiation emitted by the radiation source enters the gas measuring chamber. The radiation entering the gas measuring chamber has wavelengths that extend over an absorption band of carbon dioxide and has wavelengths that extend over a region other than the absorption band of carbon dioxide. A radiation filter is positioned (230) relative to the gas measuring chamber such that an interaction radiation path is defined between the radiation source through the gas measuring chamber to the radiation filter. A first radiation detector is positioned (240) relative to the radiation filter such that a first detection radiation path is defined that is in addition to the interaction radiation path, and a second radiation detector is positioned relative to the radiation filter such that a second detection radiation path is defined that is in addition to the interaction radiation path. The radiation filter is configured such that radiation in the first detection radiation path has a wavelength that extends over the absorption band of carbon dioxide and with an intensity of radiation that extends over the region other than the absorption band being significantly less than that in the interaction radiation path. The radiation filter is also configured such that radiation in the second detection radiation path has a wavelength that extends over the region other than the absorption band of carbon dioxide and with an intensity of radiation that extends over the absorption band being significantly less than that in the interaction radiation path. a partial pressure of carbon dioxide is determined (250) in the skin of the patient using a signal from the first radiation detector and a signal from the second radiation detector.

A device for sweat analysis includes: (1) a sensing module configured to induce sweat and generate a sensing signal responsive to a sweat concentration of a target analyte in induced sweat, the sensing module including a calibrating sensor to generate a calibration signal responsive to a secretion rate of the induced sweat; and (2) a processor connected to the sensing module, the processor configured to derive a measurement of the sweat concentration of the target analyte from the sensing signal, and to derive a normalized measurement of a blood concentration of the target analyte from the calibration signal.

A tourniquet includes a strap formed of a flexible material and shaped as a long, thin and generally flat body having a first surface and an opposed second surface, and an array of ridges extending transversely, substantially along most of the first surface. The tourniquet head includes an insertion mouth and within the mouth a flexible support and a plurality of teeth formed on the flexible support. The flexible support and the plurality of teeth providing an insertion channel in the tourniquet head for tightly receiving a free insertion end of the strap in a manner that enables the strap to be threaded through the insertion mouth with the plurality of teeth in the head being lockable on the ridges on the strap in a manner that enables a leading end of said strap to be ratcheted through the mouth in a locking direction only. A release lever enables the flexible support in the mouth to be pulled away from the ridges on the strap to allow for temporary disengaging of the teeth in the head from the ridges on the strap, to enable gradual and controlled releasing of tourniquet tension being applied on a body part to which the tourniquet has been mounted.

The described embodiments relate to a self-regulating patch for taking biopotential measurements and balancing accurate measurements and user comfort. The self-regulating patch including: a heating element operable to generate heat that causes formation of sweat at the skin surface; a biopotential sensor; an exterior surface constructed of a moisture wicking material enveloping the heating element; and a logic to concurrently activate the biopotential sensor and transition the self-regulating patch between a plurality of modes, including a comfort mode and an accuracy mode, where in the comfort mode the heating element is inactive and in the accuracy mode the heating element is active.

Devices that sense sweat and are capable of providing chronological assurance are described. The device uses at least one sensor to measure sweat or its components and to determine a sweat sampling rate. The chronological assurance is determined, at least in part, using the sweat sampling rate. The sweat sampling rate may be determined, at least in part, using a sweat volume and/or a sweat generation rate, both of which may be measured or predetermined.

The invention provides systems and methods for tissue-mounted photonics. Devices of some embodiments implement photonic sensing and actuation in flexible and/stretchable device architectures compatible with achieving long term, mechanically robust conformal integration with a range of tissue classes, including in vivo biometric sensing for internal and external tissues. Tissue-mounted photonic systems of some embodiments include colorimetric, fluorometric and/or spectroscopic photonics sensors provided in pixelated array formats on soft, elastomeric substrates to achieve spatially and/or or temporally resolved sensing of tissue and/or environmental properties, while minimize adverse physical effects to the tissue. Tissue-mounted photonic systems of some embodiments enable flexible passive or active optical sensing modalities, including sensing compatible with optical readout using a mobile electronic devices such as a mobile phone or tablet computer.

A detection system (100) detects at least ethanol in human sweat. The detection system (100) includes at least one sensor (105) that is an electrochemical gas sensor. The at least one sensor (105) is configured at least for the detection of ethanol. The detection system (100) further includes a measuring chamber (107), in which substances excreted by the user via the user's skin can be fed via a waterproof, gas-permeable diffusion membrane to the at least one sensor (105). The detection system (100) further includes at least one seal (127), which is configured to be brought into direct contact with the skin of a user and to protect at least the measuring chamber (107) from environmental effects.

A device for determining the amount or concentration of an analyte in a fluid sample and a flow rate of the fluid sample in a channel is provided. The device includes a chamber including a channel and an opening the channel in fluid communication with the opening. The device further includes a wicking component positioned adjacent to the opening configured to receive an amount of fluid from the channel. The device may further include an analyte sensor positioned on the wicking component, the analyte sensor configured to detect an analyte in fluid in contact with the analyte sensor, wherein the wicking component is configured to contact the amount of fluid with the analyte sensor. Alternatively the device may include at least one pair of electrodes configured to determine a flow rate of the fluid in the channel.

Described are methods and devices (100) for measuring a sweat property of skin (12) in response to at least one test material or component (172, 174, 176, 178). Embodiments of the device include a plurality of different sweat stimulation sites. The Sweat stimulation sites may include one or more sweat stimulant reservoirs (142, 144, 146, 148) configured to deliver a sweat stimulant to the surface of the skin (12). Embodiments may also include at least one electrode (150, 152, 154, 156, 158) for measuring a sweat property or to iontophoretically deliver the sweat stimulant from the reservoir (142, 144, 146, 148). In embodiments, the sweat stimulant is selected from acetylcholine, carbachol, methacholine, bethanechol, muscarine, pilocarpine, oxotremorine, and combinations thereof.

The invention provides systems and methods for tissue-mounted photonics. Devices of some embodiments implement photonic sensing and actuation in flexible and/stretchable device architectures compatible with achieving long term, mechanically robust conformal integration with a range of tissue classes, including in vivo biometric sensing for internal and external tissues. Tissue-mounted photonic systems of some embodiments include colorimetric, fluorometric and/or spectroscopic photonics sensors provided in pixelated array formats on soft, elastomeric substrates to achieve spatially and/or or temporally resolved sensing of tissue and/or environmental properties, while minimize adverse physical effects to the tissue. Tissue-mounted photonic systems of some embodiments enable flexible passive or active optical sensing modalities, including sensing compatible with optical readout using a mobile electronic devices such as a mobile phone or tablet computer.