Apparatus for reduction of bias in amperometric sensors
First Claim
1. Apparatus for analyte determination in a test sample comprising:
- amperometric sensor means for receiving the test sample;
timer means for identifying a burnoff time interval, a delay time interval, and a read time interval;
said read time interval following said delay time interval;
voltage potential means responsive to said timer means for applying a first voltage potential which is a burnoff voltage potential to said amperometric sensor means during said burnoff time interval and for applying a second voltage potential which is a read voltage potential to said amperometric sensor means during said read time interval;
said burnoff voltage potential and said read voltage potential having a common polarity;
means responsive to said timer means and said voltage potential means for measuring a first current i1 resulting from said applied burnoff voltage potential and a second current i2 resulting from said applied read voltage potential; and
means responsive to said current measuring means for determining an analyte value of the test sample.
1 Assignment
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Accused Products
Abstract
Apparatus and method are provided for determining the concentration of an analyte in a fluid test sample by applying the fluid test sample to the surface of a working electrode which is electrochemically connected to a reference electrode which surface bears a composition comprising an enzyme specific for the analyte. A mediator is reduced in response to a reaction between the analyte and the enzyme. An oxidizing potential is applied between the electrodes to return at least a portion of the mediator back to its oxidized form before determining the concentration of the analyte to thereby increase the accuracy of the analyte determination. Following this initially applied potential, the circuit is switched to an open circuit or to a potential that substantially reduces the current to minimize the rate of electrochemical potential at the working electrode. A second potential is applied between the electrodes and the current generated in the fluid test sample is measured to determine analyte concentration. Optionally, the accuracy of the analyte determination is further enhanced algorithmically.
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Citations
5 Claims
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1. Apparatus for analyte determination in a test sample comprising:
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amperometric sensor means for receiving the test sample; timer means for identifying a burnoff time interval, a delay time interval, and a read time interval;
said read time interval following said delay time interval;voltage potential means responsive to said timer means for applying a first voltage potential which is a burnoff voltage potential to said amperometric sensor means during said burnoff time interval and for applying a second voltage potential which is a read voltage potential to said amperometric sensor means during said read time interval;
said burnoff voltage potential and said read voltage potential having a common polarity;means responsive to said timer means and said voltage potential means for measuring a first current i1 resulting from said applied burnoff voltage potential and a second current i2 resulting from said applied read voltage potential; and means responsive to said current measuring means for determining an analyte value of the test sample. - View Dependent Claims (2, 3, 4, 5)
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Specification