A generic implantable puck (300) that can be used with a number of biosensor configurations. This generic implantable potentiostat telemetry unit (the puck) can also be part of a system to detect glucose concentrations. An electrochemical system partially implantable into a body for detecting glucose concentrations therein is presented. The system comprises an electrochemical sensor (200), a transmitting puck including an electric circuit connected to the electrochemical sensor for transmitting a signal indicative of the glucose concentrations in the body. There is at least one receiver (800) for receiving the signal from the transmitting puck and a computer system coupled to the at least one receiver for processing the signal for patient diagnosis and treatment.

Generic integrated implantable potentiostat telemetry unit for electrochemical sensors

A method and apparatus for determining the operating condition of a gas sensor apparatus including an amperometric electrochemical sensor operating normally in a potentiostat mode. By coating the sensor with a conductive coating or by varying one or more operating conditions, a response of the sensor can be determined and compared with sensor response while operating normally. This testing enables abnormalities in sensor operation to be determined, and failure of the sensor to be predicted.

Method and apparatus for diagnosing the condition of a gas sensor

A multilayer film (10) in which a plurality of Si1-x1-y1Gex1Cy1 (0 ≤ x1 y2) layers having a composition having a greater proportion of Ge, such as Si0.2Ge0.8 layer (12), are alternately laminated. The multilayer film allows the expansion of the range wherein a semiconductor crystal layer having C atoms in lattice positions is capable of functioning as a SiGeC layer to a composition having a greater proportion of Ge.

Semiconductor crystal film and method for preparation thereof

A potentiostat for an amperometric sensor uses a voltage-controlled current source (VCCS), which may be either unidirectional or, preferably, bidirectional. An error amplifier compares the potential of the sensor's reference or counter electrode, relative to ground potential, to a set-point potential. The error voltage serves as an input to the VCCS. The output of the VCCS--a current proportional to the error voltage--is supplied to the sensor's auxiliary electrode. In a steady state, the error voltage is just large enough to supply current that is equal to the current through the sensor's working and auxiliary (or counter) electrodes. The error voltage can either serve directly as an output voltage or it can be amplified without introducing a feed-back loop disturbance. The VCCS permits direct grounding of the sensor's working electrode and operation of the error amplifier at a low or moderate gain, so as to increase the circuit's frequency response and reduce the probability of oscillation. Also, in conjunction with an adjustable low-pass filter, the VCCS permits optimization of the system's frequency response so as to yield improved stability.

Potentiostatic apparatus and methods

A system and method for calibrating a sensor of a characteristic monitoring system in real time utilizes a self-calibration module for periodic determination of, and compensation for, the IR drop across unwanted resistances in a cell. A current-interrupt switch is used to open the self-calibration module circuit and either measure the IR drop using a high-frequency (MHz) ADC module, or estimate it through linear regression of acquired samples of the voltage across the sensor's working and reference electrodes (Vmeasured) over time. The IR drop is then subtracted from the closed-circuit value of Vmeasured to calculate the overpotential that exists in the cell (Vimportant). Vimportant may be further optimized by subtracting the value of the open-circuit voltage (Voc) across the sensor's working and reference electrodes. The values of Vmeasured and Vimportant are then controlled by respective first and second control units to compensate for the IR drop.

Real-time self-calibrating sensor system and method

An improved potentiostat for use with electrochemical cells provides dynamic protection of both the electrochemical cell elements and the sensitive potentiostat components from any significant voltage or current overload. A comparator compares the potentiostat input voltage with the electrochemical cell reference electrode voltage. When the reference electrode voltage becomes substantially different from the potentiostat input voltage and exceeds a certain preset value, the comparator activates a control means that causes the cell current to go to zero. This system provides dynamic protection even as the input voltage varies.

A potentiostat for use with electrochemical cells

An improved instrument for use with an electrochemical cell that provides a system having enhanced stability and increased bandwidth. The instrument includes a voltage to current converter which drives the cell. The current output of the voltage to current converter is linearly proportional to the differential voltage input. The voltage to current converter drives the cell in both the potentiostatic mode and in the galvanostatic mode of operation.

Instrument for use with an electrochemical cell

Device for jointly using electromechanical cell

An improved instrument for use with an electrochemical cell that provides a system having enhanced stability and increased bandwidth. The cell (10) includes a counter electrode (16) a reference electrode (14) and a working electrode (12). The instrument includes a voltage to current converter means (18, 20) having an inverting input (28) a non-inverting input (26) and an output (Iw) connected to the counter electrode (16). The current output of the voltage to current converter means is linearly proportional to the difference between the voltages at said inputs (26, 28). The voltage to current converter drives the cell in both the potentiostatic mode and in the galvanostatic mode of operation.

Kay Keiji Kanazawa

Papers

A potentiostat for use with electrochemical cells

Instrument for use with an electrochemical cell

Device for jointly using electromechanical cell

An apparatus for controlling the electrical parameters of an electrode reaction in an electrochemical cell