Analytical test meter

Patent metadata

Field	Value
Publication number	US-9395319-B2
Application number	US-201313875487-A
Country	US
Kind code	B2
Filing date	May 2, 2013
Priority date	May 2, 2013
Publication date	Jul 19, 2016
Grant date	Jul 19, 2016

Abstract

A portable analytical test meter is designed for use with an associated analytical test strip. A test-strip-receiving module receives the analytical test strip and is electrically connected to a dummy load calibration circuit block. That block is configured to provide a dummy magnitude correction and a dummy phase correction; and a memory block is configured to store the dummy magnitude correction and the dummy phase correction. A method for calibrating a portable analytical test meter for use with an analytical test strip includes determining a dummy magnitude correction and a dummy phase correction of the portable analytical test meter using a dummy load calibration circuit block of the portable analytical test meter. The dummy magnitude correction and the dummy phase correction are stored in a memory block of the portable analytical test meter. Using the stored dummy magnitude correction and stored dummy phase correction, an analyte is determined.

First claim

The invention claimed is:

1. A portable analytical test meter for use with an associated analytical test strip, the portable analytical test meter comprising:
a) a test-strip-receiving module adapted to receive the analytical test strip;
b) a dummy load calibration circuit block electrically connected to the test-strip-receiving module; and
c) a memory block;
d) wherein the dummy load circuit block is configured to provide a dummy magnitude correction and a dummy phase correction; and
e) wherein the memory block is configured to store the dummy magnitude correction and the dummy phase correction,
wherein the analytical test strip includes an analyte chamber and wherein:
a1) the test-strip-receiving module includes first and second electrical connector pins;
b1) the dummy load calibration circuit block includes:
i) a dummy load having selected electrical characteristics;
ii) an excitation source adapted to selectively provide at least one electrical signal;
iii) a demodulator adapted to produce one or more demodulated signal(s);
iv) a processor connected to receive the one or more demodulated signal(s) from the demodulator; and
v) a switching unit adapted to selectively electrically connect the excitation source to the demodulator through either the dummy load or the first and second electrical pins of the test-strip-receiving module; and

c1) the processor is programmed to:
concurrently cause the switching unit to connect through the dummy load, cause the excitation source to provide a DC signal, and record first respective value(s) of the demodulated signal(s);
determine a bias of the demodulator using the first respective value(s) and store the determined bias in the memory block;
concurrently cause the switching unit to connect through the dummy load, cause the excitation source to simultaneously provide both an AC signal and the DC signal, and record second respective value(s) of the demodulated signal(s);
determine the dummy magnitude correction and the dummy phase correction using the respective second value(s) and the determined bias of the demodulator, and store the determined dummy magnitude correction and dummy phase correction in the memory block;
detect the insertion of a test strip in the test-strip-receiving module;
concurrently cause the switching unit to connect through the first and second electrical pins, cause the excitation source to simultaneously provide both an AC signal and a DC signal, and after the insertion, record third respective value(s) of the demodulated signal(s); and
determine phase and gain modifiers of the portable analytical test meter with test strip using the third respective value(s), the determined dummy magnitude correction and the determined dummy phase correction, and the determined bias of the demodulator, and store the determined phase and gain modifiers of the portable analytical test meter with test strip in the memory block.

2. The portable analytical test meter according to claim 1 , wherein the processor is further programmed to:
apply a selected electrical signal across the first and second electrical connector pins after the test strip is detected, and concurrently record fourth respective value(s) of the demodulated signal(s);
determine one or more corrected value(s) corresponding to the fourth respective value(s) using the determined phase and gain modifiers of the portable analytical test meter with test strip, the determined dummy magnitude correction and the determined dummy phase correction, and the determined bias of the demodulator; and
process the corrected value(s) to detect presence of a fluid sample and, if the fluid sample is present, determine the analyte.

3. The portable analytical test meter according to claim 1 , wherein the processor is further programmed to:
detect the insertion of a second test strip in the test-strip-receiving module;
apply a selected electrical signal across the first and second electrical connector pins after the second test strip is detected, and concurrently record fourth respective value(s) of the demodulated signal(s);
determine one or more corrected value(s) corresponding to the fourth respective value(s) using the stored determined phase and gain modifiers of the portable analytical test meter with test strip, the stored determined dummy magnitude correction, the stored determined dummy phase correction, and the stored determined bias of the demodulator; and
process the corrected value(s) to detect presence of a fluid sample on the second test strip and, if the fluid sample is present, determine the analyte.

4. The portable analytical test meter according to claim 1 , wherein:
a) the demodulated signal(s) include a real-component signal and an imaginary-component signal;
b) the determined bias includes a real bias component and an imaginary bias component corresponding respectively to the real-component signal and the imaginary-component signal; and
c) the processor is programmed to additively combine the real bias component and the imaginary bias component with real component(s) and imaginary component(s), respectively, of the second, third, and fourth respective value(s).

5. The portable analytical test meter according to claim 4 , wherein the excitation unit provides a first AC signal, the portable analytical test meter further comprising a phase delay unit that provides a lagged signal 90° in phase behind the first AC signal, and wherein the demodulator further includes two mixer units controlled by the first AC signal, or a signal in phase therewith, and the lagged signal, respectively, the mixer units being operative to provide the real-component signal and the imaginary-component signal, respectively.

6. The portable analytical test meter according to claim 1 , wherein the switching unit includes two double-throw switches, one said switch connecting the excitation source to one of a first terminal of the dummy load and the first electrical connector pin of the test-strip-receiving module, and the other said switch connecting an input of the demodulator to one of a second terminal of the dummy load and the second electrical connector pin of the test-strip-receiving module.

7. The portable analytical test meter according to claim 1 , wherein the excitation source is configured to provide voltage signals, the demodulator further comprising a transimpedance amplifier to measure current(s) and provide corresponding voltage(s), and the demodulator being adapted to provide the demodulated signal(s) using the voltage(s).

8. The portable analytical test meter according to claim 1 , wherein the dummy load calibration block includes a resistor.

9. The portable analytical test meter according to claim 8 , wherein the resistor is a 22KΩ precision resistor.

10. A method for calibrating a portable analytical test meter for use with an analytical test strip, the method comprising:
determining a dummy magnitude correction and a dummy phase correction of the portable analytical test meter using a dummy load calibration circuit block of the portable analytical test meter;
storing the dummy magnitude correction and the dummy phase correction in a memory block of the portable analytical test meter; and
determining an analyte using the stored dummy magnitude correction and stored dummy phase correction,
wherein the step of determining corrections includes:
receiving an analytical test strip inserted into a test-strip-receiving module of the test meter so that first and second electrical contact pads exposed on the analytical test strip electrically contact first and second electrical connector pins of the test-strip-receiving module, respectively, the analytical test strip including a sample-re

Assignees

• Lifescan Scotland Ltd

Inventors

• Guthrie Brian
• Lloyd Tim
• Gadde Yeswanth
• Strachan Alexander
• Elder David
• Massari Rossano
• Forlani Christian

Classifications

• G01N27/307 Primary

  Disposable laminated or multilayered electrodes (G01N27/3272 takes precedence) · CPC title

• G01N27/3274

  Corrective measures, e.g. error detection, compensation for temperature or hematocrit, calibration (coding of calibration information G01N33/48771) · CPC title

• G01N27/3273 Primary

  Devices therefor, e.g. test element readers, circuitry (details not specific to biochemical electrodes G01N33/4875) · CPC title

• G01N27/327 Primary

  Biochemical electrodes {, e.g. electrical or mechanical details for in vitro measurements} · CPC title