Non-or minimally invasive monitoring methods

Abstract

An apparatus for sensing an analyte is described, wherein the apparatus includes an interface contact element that is used to establish an interface with a quantity of body fluid. The interface contact element is adapted to facilitate diffusion of a target analyte across the interface essentially free of net mass fluid transport. The quantity of body fluid is exposed to the interface contact element through micro-pathways. The apparatus can also include a sensing material adapted to sense the target analyte with at least one analytical method. Methods for using the apparatus in a non- or minimally invasive monitoring technique are also described. FIG. (1) illustrates a non-limiting embodiment of the apparatus used to test the principles of the invention.

Description

FIELD OF THE INVENTION The present invention relates to methods of continuous or rapid intermittent monitoring of body fluid for the presence and / or concentration of target analytes. More particularly, the invention relates to using diffusion of a target analyte from a body fluid such as interstitial fluid via a micro-pathway, and an interface contact element that is used to establish an equilibrium of analyte concentration between the body fluid and the interface contact element. The concentration of the target analyte can then be measured using a sensing material, thereby providing for continuous analyte monitoring such as continuous glucose monitoring by diabetic or hypoglycemic subjects. BACKGROUND OF THE INVENTION A number of tests are routinely performed on humans to evaluate the amount or existence of substances present in blood or other body fluids. These tests typically rely on physiological fluid samples removed from a subject, either using a syringe or by pricking the s...

AI Technical Summary

Benefits of technology

The present invention provides an apparatus and method for continuous or rapid intermittent monitoring of the concentration of a target analyte in a body fluid essentially without net mass fluid transport. This is achieved by diffusion of the target analyte between the body fluid and an interface contact element. The body fluid is exposed via micro-pathways that allow the body fluid to interface with the interface contact element. A portal generator, such as a particle injection device, is used to create such micro-pathways. A sensor (e.g., a hydrogel), comprising the interface contact element and a sensing material, can be incorporated into a patch that sits on the subject's skin. The patch can be configured to connect to a detector that provides quantitative results, such as by capturing an electrical signal. An instrument comprises the sensor and detector. Diffusion allows for an analytical measurement of concentration on a continuous or intermittent basis as the concentration gradient between the body fluid and interface contact element approaches continuous equilibrium. The access realized from this method allows much more frequent sampling and yields a more accurate result than existing interstitial fluid technology, and a painless measurement as opposed to the pain involved in whole blood sampling.

Problems solved by technology

On the other hand, improper administration of insulin therapy can result in hypoglycemic episodes, which can result in coma and death.

However, the pain and inconvenience associated with this blood sampling, has lead to poor patient compliance, despite strong evidence that precise-maintained control dramatically reduces long-term diabetic complications.

In fact, these considerations can often lead to an abatement of the monitoring process by the diabetic.

Due to the low volume of interstitial fluid in the tissue, expression of a sample through pierced skin can give inaccurate results depending upon the sample size required and the amount of trauma to the tissue from the collection procedure.

Moreover, such methods cannot provide a continuous or even “real-time” monitoring of the glucose concentration in the interstitial fluid because of the time involved to access sufficient interstitial fluid to provide a measurable amount of glucose.

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