Abstract: One aspect of the present disclosure relates to an analyte sensor device. The analyte sensor device can include an optode layer that undergoes an optical change in the presence of an analyte. The analyte sensor device can also include a selectively-permeable membrane encapsulating the optode layer to form a stable membrane that that minimizes fouling of the analyte sensor device. The analyte sensor device can also include a plurality of microparticles that suppress a background physical interference on a detection of the optical change of the optode layer.

Abstract: One aspect of the present disclosure relates to an analyte sensor device. The analyte sensor device can include an optode layer that undergoes an optical change in the presence of an analyte. The analyte sensor device can also include a selectively-permeable membrane encapsulating the optode layer to form a stable membrane that that minimizes fouling of the analyte sensor device. The analyte sensor device can also include a plurality of microparticles that suppress a background physical interference on a detection of the optical change of the optode layer.

Abstract: A signal isolating device for an input digital signal has a first photo-coupler which is activated by the differential pulse produced at the leading edge of the digital signal and a second photo-coupler which is activated by the differential pulse produced at the trailing edge of the digital signal. A positive feedback system is connected in push-pull fashion with the photo-couplers for producing an output digital signal that corresponds to the input digital signal. The positive feedback system may be implemented by a buffer that includes a resistor for keeping the buffer in a stable state even when both of the photo-couplers are non-conductive.

Abstract: A method and apparatus for calculating a ratio, R, having a first capacitance value, C.sub.1, in inverse relation to a second capacitance value, C.sub.2, where C.sub.1 and C.sub.2 are the capacitance values of a first capacitor and a second capacitor respectively. The first and second capacitors each have an independent electrode and share a common electrode. An AC voltage is applied to the common electrode producing first and second AC current signals at the two independent electrodes. A dual switched-capacitor integrated circuit and two current to frequency converters respectively convert the first and second AC current signals to first and second frequency signals having values f.sub.1 and f.sub.2. A microprocessor receives the first and second frequency signals and calculates R from f.sub.1 and f.sub.2.