Abstract: 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.

Abstract: A burette (10, 110, 200) suitable for delivery of a reagent into a target solution (50) employs diffusion for delivering the reagent. The reagent is in the form of a solution, which is combined with a matrix material (22), such as a gel or porous ceramic. A membrane (32) covers a delivery outlet (20) to the burette. In one embodiment, the delivery outlet comprises a plurality of fine bores (36), each one filled with or covered by a membrane (38). Stirring of the burette or target solution is achieved with a stirring means (104, 106). A heating or cooling means (80) heats a tip (16) of the burette.

Abstract: A method for solving deconvolution problems where it is desired to reconstruct a signal over a time range or another variable of interest involves comparing shapes of measured and reconstructed plots. The optimization method is based on minimizing the error in shape (as opposed to the square errors in amplitude). A shape approach method characterizes similarity of two functions by computing the angle between the two when they are treated as two vectors in the n dimensional space where n is the number of data points it is desired to consider from both functions (the functions themselves may consist of more than n data points). A new approximation is then created by trying to decrease the disimilarity between the actual and predicted functions. This dissimilarity is measured as the angle between the two corresponding vectors, so the measure of dissimilarity is the size of the angle.

Abstract: A small liquid sample (24) to be tested is contained within an annulus (18) on the upper surface (14) of a substrate (12). In one embodiment, a reagent diffuses into the sample through a membrane (28) in a junction hole (26), the junction hole connecting upper (14) and lower (16) surfaces of the substrate. Optical measuring equipment (70, 72) detects a measurable change in an optical property of the sample. In an alternate embodiment, a flow of gas (30), directed at the small liquid sample (24), causes the sample to flow in a controlled manner over the surface of an electrode (20), disposed on the substrate surface (14). In another alternate embodiment, a special averaging electrode (20) is disposed in a non-homogeneous sample (24). Highly reproducible and accurate hydrodynamic electrochemical studies and analyses of microliter size samples are thus achievable, without the need for moving mechanical parts.