Patent EP-2283774-A1 (EP)
IPC: A61B5/151
Filed: 2009-08-13
Abstract: The test element for making a puncture wound in a body part, for receiving a body fluid sample from the body part and for analyzing using a reagent system, whose reaction guides with analytes contained in the body fluid for a modification of one of the characteristic measured parameters of the test element optically measurable for the desired analytical results, comprises a lancing element (3) and a testing field (5), which contains a part of the reagent system. The lancing element has a nib at one end of the lancing element for making the wound in the body part, and a capillary structure. The test element for making a puncture wound in a body part, for receiving a body fluid sample from the body part and for analyzing using a reagent system, whose reaction guides with analytes contained in the body fluid for a modification of one of the characteristic measured parameters of the test element optically measurable for the desired analytical results, comprises a lancing element (3) and a testing field (5), which contains a part of the reagent system. The lancing element has a nib at one end of the lancing element for making the wound in the body part, and a capillary structure that is designed, so that the body fluid penetrates into the capillary structure after inserting the nib of the lancing element into the skin. The lancing element and the testing field are positionable relative to each other in a liquid transfer position, so that the testing field fluidically contacts to a part of the capillary structure of the lancing element. The body fluid penetrating into the capillary structure is transferred to the testing field. The testing field comprises a transparent supporting layer (100) and a testing layer introduced on the supporting layer by coating, where the side of the testing layer turned away from the supporting layer forms the fluid entry side, which is turned towards the capillary structure in the liquid transfer position and directly adjoins to the capillary structure in the liquid transfer position. The testing field is fixed onto the lancing element, so that the lancing element and the testing field are fluidically contacted in a permanent manner. The testing layer includes two partial layers, where a first partial layer coated on the supporting layer is a reaction layer (102) and a second partial layer coated on the supporting layer is an opaque blocking layer (103). The reaction layer and the opaque blocking layer contain an enzyme and a color formation reagent (indicator). The quantity of the enzyme in the reaction layer is higher than in the blocking layer and the quantity of the indicator in the reaction layer is less than in the blocking layer. A component of the reagent system such as enzyme is bound to the supporting layer of the testing field. The capillary structure includes a two-dimensional matrix structure with 100 cells having cell cavities, and a capillary channel, through which the body fluid is transferred to the matrix structure after inserting the nib of the lancing element into the skin. The largest dimension of the cell cavity of the matrix structure is less than the average width of the capillary channels. The cell cavities vertical to the extension of the matrix structure have a defined height, by which the least value of the layer thickness of the fluid layer is enabled. The cells are opened at a transfer side of the matrix structure adjoined to the fluid entry side. The matrix structure is arranged parallel and adjacent to a partial length of the capillary channel. The cells of the matrix structure have cell openings at the fluid entry side opposite to the transfer side turned towards the capillary channel, so that the fluid penetrates through the cell openings in the cell cavity of the matrix structure. The thickness of the testing layer is 20 mu m. The cell cavity of the matrix structure consistently broadens towards the transfer side. The capillary channel and the matrix structure are produced in a common production process step by etching or etching and laser cutting. Independent claims are included for: (1) an analysis system for analyzing a body fluid from a body part; and (2) a method for producing a lancing element with a capillary channel for making a puncture wound in a body part.