Spreading layer and humidity control layer for enhancing sensor performance

Inventors

Ramamurthy, Narayanan • He, Huarui • Lin, Chao

Assignees

Opti Medical Systems Inc

Abstract

The invention is directed to optical sensors for measuring clinically relevant analytes, their methods of manufacture, and their various uses. In an effort to develop a dry calibration method for the optical sensors of the invention it is discovered that water content inside or in the immediate vicinity of a such a sensor can have a major impact on fluorescence intensity (i.e., a sensor's response in the dry state). Thus, one of the objectives of the invention is the elimination of the bias of sensor responses measured at different humidity environments.

Core Innovation

The invention relates to a dry-calibration optical fluorescence sensor architecture for clinical analyte measurement that uses a multi-layered laminate and an indicator layer to generate an optical fluorescence-based response. A specific problem is described in which water content and/or humidity present near the sensor biases dry fluorescence intensity, leading to response variation as ambient humidity changes.

To address humidity-dependent bias, the laminate includes a humidity control layer having opposing sides and being effective to inhibit undesirable effects of varying levels of humidity present on one side of the layer. The humidity control layer comprises a water-insoluble, porous matrix with channels or through holes extending between opposing sides, where one or more water-soluble, solid, polymeric substances fill a substantial portion of the channels or through holes.

The invention further defines a spreading layer effective to promote a desirable rate of spreading of a liquid sample applied on one surface of the spreading layer. The spreading layer comprises a water-insoluble, porous matrix with channels or through holes extending between opposing surfaces, one or more water-soluble, solid, polymeric substances filling a substantial portion of the channels or through holes, and one or more hydrophilic, super absorbent materials. The disclosed laminate sequence includes an indicator layer, an overcoat layer, the humidity control layer, a sample loading layer, and the spreading layer.

Claims Coverage

The independent claim defines a multi-layered laminate with two core functional regions: a humidity control layer configured to inhibit humidity effects and a spreading layer configured to promote desirable liquid spreading. It contains at least two sets of structural limitations integrated into a five-layer ascending sequence.

Overall, the claim coverage centers on a five-layer laminate that integrates a humidity control layer built from a water-insoluble porous matrix with channels or through holes filled by water-soluble solid polymer to inhibit humidity effects, together with a spreading layer that uses a porous, channel-based matrix filled with water-soluble solid polymer and combined with hydrophilic super absorbent materials to promote liquid spreading.

Stated Advantages

Documented Applications