Body fluid collection and analysis

Abstract

The invention relates to attachable body fluid collection devices, each comprising at least one storage structure for, when in use, storing a body fluid sample secreted by a body fluid secreting surface. The or at least one of the storage structure comprises silicon. Particular emphasis is placed on sweat patches and techniques for analyzing sweat.

Description

BACKGROUND OF THE INVENTION [0001] This invention relates to the collection of body fluids and to the analysis of body fluids. More specifically this invention relates to the collection of sweat and to the analysis of sweat. [0002] The analysis of body fluids, of animals or humans, may be of value in the detection of disease, or substances, such as drugs, absorbed by a subject. Blood, saliva, urine, and sweat have all been used for such analysis. Although blood is the most commonly tested fluid, sweat probably provides the most inexpensive, safe, and convenient source of a number of analytes. Devices used to collect sweat, are commonly referred to as sweat patches. [0003] In addition to water and electrolytes, sweat contains trace elements such as zinc, cadmium and lead. The trace elements found in sweat probably originate from blood serum. Labile metals can dissociate from proteins under the influence of the concentration gradient existing across blood capillaries, and diffuse thro...

AI Technical Summary

Benefits of technology

[0058] The use of a storage means comprising porous silicon may be advantageous since the porous silicon may perform a dual function of filtration and storage. The porous silicon in the region of the skin acting as a filter by, for example, preventing entry of skin cells into the part of the porous silicon to be analyzed, but allowing passage of the sweat sample. Porous silicon also opens the way for the use of biasing to assist with deposition of the body fluid sample on the storage means. It also allows the use of biasing to assist with the separation of the sweat sample prior to analysis of the sample.

[0066] Derivatization may be selected to allow wetting of the or at least one of the storage means. Alternatively derivatization may be selected to enhance stability of the porous silicon against dissolution or corrosion by the body fluid. The derivatization may be such that the porous silicon selectively binds to one component, or a limited number of components, in the body fluid.

[0075] The use of reference and derivatized storage means may be advantageous. Analysis of both the reference and derivatized storage means may allow comparison of the two types of storage means to determine whether binding to the sweat element or compound has occurred.

[0098] The step (c) may comprise the step of applying a bias to the silicon sample in such a manner that the rate of collection of the sweat sample is accelerated, relative to the rate of deposition when the silicon sample is at earth potential. The step (c) may comprise the step of applying a bias to the porous silicon in such a manner that the rate of deposition of the sweat sample on the silicon is accelerated, relative to the rate of deposition when the silicon sample is at earth potential.

[0107] The step of collecting the body fluid sample may comprise the step of increasing the rate of collection, relative to the rate of collection when the sample of silicon is at earth potential, by applying a bias to the sample of silicon.

Problems solved by technology

The design of sweat patches is a complex process.

The main problem addressed by U.S. Pat. No. 4,756,314 is the large variation in sweat uptake that may occur from individual to individual.

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