Rapid-read gated amperometry devices

Abstract

A sensor system, device, and methods for determining the concentration of an analyte in a sample is described. Input signals including multiple duty cycles of sequential excitation pulses and relaxations are input to the sample. One or more signals output from the sample within 300 ms of the input of an excitation pulse may be correlated with the analyte concentration of the sample to improve the accuracy and/or precision of the analysis. Determining the analyte concentration of the sample from these rapidly measured output values may reduce analysis errors arising from the hematocrit effect, mediator background, and other error sources.

1 - 39 . (canceled) 
     
     
         40 . A handheld measuring device adapted to receive a sensor strip for determining a concentration of an analyte in a sample, the handheld measuring device comprising:
 at least two electrodes configured to contact the sample; and   electrical circuitry in electrical communication with the at least two electrodes, the electrical circuitry including a processor in electrical communication with a signal generator and a computer readable storage medium,   wherein the processor is programmed to:   cause the signal generator to apply an electrical input signal to the sample, the electrical input signal including one or more excitation pulses and one or more relaxations;   measure an electrical output signal responsive to a measurable species within 300 milliseconds from a start of one of the one or more excitation pulses, the measurement of the electrical output signal terminating prior to an end of the one excitation pulse of the one or more excitation pulses, a pulse width of the one excitation pulse of the one or more excitation pulses being at least 0.1 seconds; and   determine the concentration of the analyte in the sample based on the measured electrical output signal.   
     
     
         41 . The handheld measuring device of  claim 40 , wherein the pulse width of the one excitation pulse of the one or more excitation pulses is from 0.3 to 0.8 seconds. 
     
     
         42 . The handheld measuring device of  claim 40 , wherein the pulse width of the one excitation pulse of the one or more excitation pulses is from 0.2 to 1 second. 
     
     
         43 . The handheld measuring device of  claim 40 , wherein the measuring of the electrical output signal occurs within 175 milliseconds from the start of the one excitation pulse of the one or more excitation pulses. 
     
     
         44 . The handheld measuring device of  claim 40 , wherein the measuring of the electrical output signal occurs within 60 to 150 milliseconds from the start of the one excitation pulse of the one or more excitation pulses. 
     
     
         45 . The handheld measuring device of  claim 40 , wherein the processor is further programmed to apply at least one data treatment to at least one current of the electrical output signal, wherein the at least one data treatment determines at least one of a decay rate, a K constant, and a ratio value. 
     
     
         46 . The handheld measuring device of  claim 40 , wherein the electrical input signal has at least 3 duty cycles within 30 seconds. 
     
     
         47 . The handheld measuring device of  claim 40 , wherein the electrical output signal includes a transient decay, and wherein the determining of the analyte concentration includes determining the analyte concentration from the transient decay of the electrical output signal. 
     
     
         48 . The handheld measuring device of  claim 40 , wherein at least one of the one or more relaxations includes a current flow reduction to at least (i) one-half of a current flow at an excitation maxima of the one or more excitation pulses, or (ii) an order of magnitude less than the current flow at the excitation maxima of the one or more excitation pulses. 
     
     
         49 . The handheld measuring device of  claim 40 , wherein at least one of the one or more relaxations includes zero current flow or an open circuit. 
     
     
         50 . A handheld measuring device adapted to receive a sensor strip for determining a concentration of an analyte in a sample, the handheld measuring device comprising:
 at least two electrodes configured to contact the sample; and   electrical circuitry in electrical communication with the at least two electrodes, the electrical circuitry including a processor in electrical communication with a signal generator and a computer readable storage medium,   wherein the processor is programmed to:   cause the signal generator to apply an electrical input signal to the sample, the electrical input signal including one or more excitation pulses and one or more relaxations;   measure an electrical output signal responsive to a measurable species within 300 milliseconds from a start of one of the one or more excitation pulses, the measurement of the electrical output signal terminating while the one excitation pulse of the one or more excitation pulses is still being applied to the sample, wherein a pulse width of the one excitation pulse of the one or more excitation pulses is at least 0.1 seconds;   determine the concentration of the analyte in the sample based on the measured electrical output signal.   
     
     
         51 . The handheld measuring device of  claim 50 , wherein the pulse width of the one excitation pulse of the one or more excitation pulses is from 0.3 to 0.8 seconds. 
     
     
         52 . The handheld measuring device of  claim 50 , wherein the pulse width of the one excitation pulse of the one or more excitation pulses is from 0.2 to 1 second. 
     
     
         53 . The handheld measuring device of  claim 50 , wherein the measuring of the electrical output signal occurs within 175 milliseconds from the start of the one excitation pulse of the one or more excitation pulses. 
     
     
         54 . The handheld measuring device of  claim 50 , wherein the measuring of the electrical output signal occurs within 60 to 150 milliseconds from the start of the one excitation pulse of the one or more excitation pulses. 
     
     
         55 . The handheld measuring device of  claim 50 , wherein the processor is further programmed to apply at least one data treatment to at least one current of the electrical output signal, wherein the at least one data treatment determines at least one of a decay rate, a K constant, and a ratio value. 
     
     
         56 . The handheld measuring device of  claim 50 , wherein the electrical input signal has at least 3 duty cycles within 30 seconds. 
     
     
         57 . The handheld measuring device of  claim 50 , wherein the electrical output signal includes a transient decay, and wherein the determining of the analyte concentration includes determining the analyte concentration from the transient decay of the electrical output signal. 
     
     
         58 . The handheld measuring device of  claim 50 , wherein at least one of the one or more relaxations includes a current flow reduction to at least (i) one-half of a current flow at an excitation maxima of the one or more excitation pulses, or (ii) an order of magnitude less than the current flow at the excitation maxima of the one or more excitation pulses. 
     
     
         59 . The handheld measuring device of  claim 50 , wherein at least one of the one or more relaxations includes zero current flow or an open circuit.