315 results about "Interstitial fluid" patented technology

A glucose sensor in the form of a skin patch 2 has a microneedle 4 which painlessly penetrates the skin to draw out interstitial fluid. The interstitial fluid passes to a common entrance port 7. A series of microchannels 8 is provided on the skin patch. The fluid drawn onto the patch is selectively switched between a number of microchannels 8 by means of electro-osmotic pumps 10 and hydrophobic gates 12. Each microchannel 8 has an electrochemical detector 11 for sensing gluocse concentration. Also disclosed is a monlithic device with an integrated lance 83.

A system for extracting a bodily fluid sample (e.g., an interstitial fluid [ISF] sample) and monitoring an analyte therein includes a disposable cartridge and a local controller module. The disposable cartridge includes a sampling module adapted to extract a bodily fluid sample and an analysis module adapted to measure an analyte (e.g., glucose) in the bodily fluid sample. The local controller module is in electronic communication with the disposable cartridge and is adapted to receive and store measurement data from the analysis module. An ISF extraction device includes a penetration member configured for penetrating and residing in a target site of a user's skin layer and, subsequently, extracting an ISF sample therefrom. The device also includes a pressure ring(s) adapted for applying pressure to the user's skin layer in the vicinity of the target site. The device is configured such that the pressure ring(s) is capable of applying pressure in an oscillating manner whereby an ISF glucose lag of the ISF sample extracted by the penetration member is mitigated. A method for extracting ISF includes providing an ISF fluid extraction device with a penetration member and a pressure ring(s). Next, a user's skin layer is contacted by the pressure ring(s) and penetrated by the penetration member. An ISF sample is then extracted from the user's skin layer while pressure is being applied in an oscillating manner by the pressure ring(s). The oscillating pressure mitigates an ISF glucose lag of the extracted ISF sample extracted.

An interstitial fluid (ISF) extraction device includes a penetration member configured for penetrating a target site of a user's skin layer and, subsequently, residing in the user's skin layer and extracting an ISF sample therefrom and at least three concentrically-arranged pressure rings, each adapted for applying pressure to the user's skin layer in the vicinity of the target site while the penetration member is residing in the user's skin layer. In addition, the ISF extraction device is configured such that (i) the pressure rings apply pressure in an oscillating manner with asymmetric deployment and retraction cycles and (ii) only one of the at least three concentrically-arranged pressure rings is deployed at a time, thereby mitigating an ISF glucose lag of the ISF sample extracted by the penetration member.

An apparatus for the continuous measurement of glucose and lactate in interstitial fluids including a glucose measurement cell, an A / D conversion block, a memory block and a bi-directional communication between the interface block and an external calculation unit.

The invention disclosed in this application is a method and device for combining the sampling and analyzing of sub-dermal fluid samples, e.g., interstitial fluid or whole blood, in a device suitable for hospital bedside and home use. It is applicable to any analyte that exists in a usefully representative concentration in the fluid, and is especially suited to the monitoring of glucose.

Improved microneedle arrays are provided having a sufficiently large separation distance between each of the individual microneedles to ensure penetration of the skin while having a sufficiently small separation distance to provide high transdermal transport rates. A very useful range of separation distances between microneedles is in the range of 100-300 microns, and more preferably in the range of 100-200 microns. The outer diameter and microneedle length is also very important, and in combination with the separation distance will be crucial as to whether or not the microneedles will actually penetrate the stratum corneum of skin. For circular microneedles, a useful outer diameter range is from 20-100 microns, and more preferably in the range of 20-50 microns. For circular microneedles that do not have sharp edges, a useful length for use with interstitial fluids is in the range of 50-200 microns, and more preferably in the range of 100-150 microns; for use with other biological fluids, a useful length is in the range of 200 microns—3 mm, and more preferably in the range of 200-400 microns. For circular microneedles having sharp side edges, a useful length for use with interstitial fluids is in the range of 50-200 microns, and more preferably in the range of 80-150 microns; for use with other biological fluids, a useful length is again in the range of 200 microns—3 mm, and more preferably in the range of 200-400 microns. For solid microneedles having a star-shaped profile with sharp edges for its star-shaped blades, a useful length for use with interstitial fluids is in the range of 50-200 microns, and more preferably in the range of 80-150 microns; for use with other biological fluids, a useful length is again in the range of 200 microns—3 mm, and more preferably in the range of 200-400 microns, while the radius of each of its blades is in the range of 10-50 microns, and more preferably in the range of 10-15 microns.

A method of detecting at least one analyte in extra-cellular spaces includes the step of inserting a microprobe through the stratum corneum toward the stratum basale of the skin of a subject into extra-cellular spaces containing interstitial fluid having at least one analyte to be detected, said microprobe having a diameter at its tip no larger than approximately 10-50 microns. The method further includes optically testing for a predetermined analyte in the extra-cellular space adjacent the distal end of the microprobe without drawing a sample of the interstitial fluid. Preferably the microprobe body includes a sensor layer covering the distal optical tip of the microprobe body, the sensor layer being adapted to interact with a predetermined analyte to be detected in the interstitial fluid, and an optical detector responsive to interaction of the sensor layer with the predetermined analyte to signal detection of said predetermined analyte.

In vivo or in vitro monitoring of chemical and biochemical species (e.g., pH, or glucose levels) in the interstitial fluid of patients or in a sample of a fluid to be analyzed is provided by a probe (10, 70, 210, 270). For in vivo monitoring, the probe is readily inserted by a minimally invasive method. Optical or electrochemical sensing methods are employed to detect a physical or chemical change, such as pH, color, electrical potential, electric current, or the like, which is indicative of the concentration of the species or chemical property to be detected. Visual observation by the patient may be sufficient to monitor certain biochemicals (e.g., glucose) with this approach. A CAP membrane allows high enzyme loadings, and thus enables use of microminiature probes, and / or diagnosis of low levels of the analyte(s), with sufficient signal-to-noise ratio and low background current.

An apparatus for detection and quantitation of an electrochemically-detectable analyte, such as glucose, in blood or interstitial fluid includes a meter unit, a lancet and an electrochemical sensor. Of these components, the meter is preferably reusable, while the lancet and the electrochemical sensor are preferably incorporated in assemblies intended for single-use. The meter unit has a housing, within which a lancet is engaged with a mechanism for moving then lancet; a connector disposed within the housing for engaging an electrochemical sensor specific for the analyte and transmitting a signal indicative of the amount of analyte, and a display operatively-associated with a connector for displaying the amount of the analyte to user. The electrochemical sensor is adapted for detection of a particular analyte. In addition, the electrochemical sensor has an absorptive member for uptake of a sample of blood or interstitial fluid. In one version, the lancet moves from a initial position to a piercing position in which skin of the user is pierced and optionally back to a retracted position. The electrochemical sensor is disposed such that the absorptive member takes up a sample from the pierced skin of the user when it is pierced by the lancet without movement of the apparatus. In an alternative version, the lancet is a hollow cannula through which blood or interstitial fluid is transported from the puncture site to an absorbent portion of the electrochemical sensor. In either version, the apparatus provides single-step operation in which sample acquisition and analysis occur as a result of the single action of pressing, the apparatus against the users skin.

An apparatus and method is disclosed for obtaining and measuring constituents in a sample of body fluid. The apparatus includes a member which is sized to penetrate into at least the dermal layer of skin to collect a sample of body fluid located within the dermal layer.

According to the present invention, a method for enhancing transdermal transport is disclosed. The method includes the steps of increasing a permeability of an area of a membrane with a permeabilizing device. The membrane may be, inter alia, biologic skin or synthetic skin. The permeabilizing device may be an ultrasound-producing device. A substance is transported into and through the area of the membrane. The substance may be a drug, a vaccine, or a component of interstitial fluid.

The invention disclosed in this application is a method and device for combining the sampling and analyzing of sub-dermal fluid samples, e.g., interstitial fluid or whole blood, in a device suitable for hospital bedside and home use. It is applicable to any analyte that exists in a usefully representative concentration in the fluid, and is especially suited to the monitoring of glucose.

A method is provided for determining the level of an analyte in the blood of an individual by measuring the level of the analyte in an interstitial fluid or in any other non blood fluid which does not contain red blood cells and adjusting the measurement value by the concentration of at least one reference analyte.

The current invention provides a device, and a method for using the device, for ensuring that a capillary or wicking fill device is fully filled. In particular this invention is directed to, but not limited to, use with capillary or wicking action filled electrochemical sensors suitable for use in analyzing blood or interstitial fluids.

The invention disclosed in this application is a method and device for combining the sampling and analyzing of sub-dermal fluid samples, e.g., interstitial fluid or whole blood, in a device suitable for hospital bedside and home use. It is applicable to any analyte that exists in a usefully representative concentration in the fluid, and is especially suited to the monitoring of glucose.

A sampling apparatus for sampling interstitial fluid includes a sampler having an external geometry selected to mate with an internal geometry of a testing apparatus such that the sampler may be inserted within the testing apparatus in a predetermined alignment and with a sampling location positioned accurately within a light path for detecting an amount of a desired constituent collected by the sampler.

Methods and devices are provided for determining a suitable site for sampling physiological fluid. In the subject methods, a potentially suitable physiological sampling site is selected, the fluid flow of the site is characterized and the site is then determined to be suitable based on the whether the site has high or low flow. Suitability may also be determined based on the type of sample obtainable from the site, where the order of the above-described steps may be altered. The subject devices include at least one site flow characterization element for determining the flow characteristics of a potential physiological sampling site and / or at least one sample type characterization element for determining whether the vasculature is arterial, venous or neither, i.e., an interstitial fluid sampling site. The subject methods and devices are particularly suited for use in the detection of physiological sampling sites in the fingers, arms, legs, earlobes, heels, feet, nose and toes. Also provided are kits that include the subject devices for use in practicing the subject methods.

The present invention may be used in test strips for measuring an analyte or indicator such as glucose in a physiological fluid such as blood, interstitial fluid, or urine. The present invention also relates to test strips incorporating an integrated lance such as a needle, blade, or other sharp or skin puncturing device. In particular, in one embodiment of the present invention, a fused link is incorporated into the test strip. The fused link may be destroyed once the test is completed, preventing reuse of the strip.