Apparatus and method for improved measurements of a monitoring device
View Patent ↗Methods and devices for improving measurements of test meter, and in particular for detecting a presence of an electrochemical sensor or strip in the test meter and a start time of an electrochemical reaction, are provided. In one exemplary embodiment of an electrochemical system includes an electrochemical sensor, a test meter, and a circuit. The circuit is configured to form an electrical connection with the electrochemical sensor such that the circuit can detect three distinct voltage ranges. The voltage ranges can be indicative of an absence of the electrochemical sensor, a presence of the sensor that is devoid of a sample, and a presence of the sensor with a sample. Test meters, methods for detecting when a sample starts to fill an electrochemical sensor for establishing when a reaction starts, and circuits for use with electrochemical strips, are also provided.
1. A test meter, comprising:
a housing;
a strip port connector attached to the housing, the strip port connector being configured to receive an electrochemical test strip and including at least one electrical connector; and
a single high impedance circuit configured for making electrochemical determinations and to electrically connect with an electrochemical test strip received in the strip port connector via the at least one electrical connector, the single high impedance circuit comprising:
a detection component in contact with a first electrical connector;
a sense resistor in electrical communication with the detection component;
a voltage reference point configured to be in electrical communication with an electrode of an electrochemical test strip in contact with a second electrical connector; and
a wetting supply in contact with a third electrical connector;
wherein the high impedance circuit is configured for detecting:
(1) a first voltage in the absence of an electrochemical test strip in electrical communication with the circuit;
(2) a second voltage in the presence of an electrochemical test strip that is devoid of bodily fluid sample in electrical communication with the circuit, wherein an electrical connection between the first electrical connector and the third electrical connector is formed; and
(3) a third voltage in the presence of an electrochemical test strip in electrical communication with the circuit, wherein an electrical connection between the first electrical connector, the second electrical connector, and the third electrical connector of the strip port connector is formed with an amount of a bodily fluid sample sufficient to perform an electrochemical test in the electrochemical test strip and in which the presence of the sample electrically couples each of the wetting supply, the sense resistor, and the voltage reference point via the electrical connectors within the defined single circuit.
2. The test meter of claim 1 , wherein an absolute value of the second voltage is less than an absolute value of the first voltage and an absolute value of the third voltage is less than the absolute value of the second voltage.
3. The test meter of claim 1 , wherein the amount of a sample sufficient to perform an electrochemical test is a minimum volume of sample sufficient to form an electrical connection between a common electrical connector of the at least one electrical connector and at least one of a first electrical connector and a second electrical connector of the at least one electrical connector.
4. The test meter of claim 1 , further comprising a waveform generator for applying voltage to react a sample disposed on an electrochemical test strip that is in the strip port connector.