Analyte collection devices and methods

• US 8,088,341 B2
• Filed: 07/25/2007
• Issued: 01/03/2012
• Est. Priority Date: 07/25/2007
• Status: Active Grant

• Current Assignee: University of Louisville
• Original Assignee: University of Louisville
• Inventors: Martin, Michael
• Primary Examiner(s): Warden, Jill
• Assistant Examiner(s): Cole, Monique
• Application Number:
  US11/881,333
• Publication Number:
  US 20090028208A1
• Time in Patent Office: 1,623 Days
• Field of Search: 422/420, 422/500, 422/109, 219/200, 242/0, 250/0, 210/9
• US Class Current: 422/500
• CPC Class Codes: G01N 1/405 by adsorption or absorption
• CPC Class Codes: G01N 2035/00366 Several different temperatures used

Abstract

An aspect of the invention is directed to an analyte collection device of the type that includes at least one plate for storing the analyte and a heating element for heating the at least one plate. An example device comprises a controller linked to the heating element that heats the at least one plate to a first temperature, takes a measurement of a property of the at least one plate, and uses the measurement to estimate one or more of the amount of the analyte on the plate and the amount of contaminant on the plate.

Claims

1. A method for operating an analyte collection device of the type that includes one or more plates for storing analyte, a heating element for heating the one or more plates, and a controller having a processor, a memory, and program instructions linked to the heating element, the controller programmed to perform the method steps of:

heating the one or more plates to a first temperature;

taking a measurement of one or more properties of the one or more plates from a detector at one or more of during the step of heating the one or more plates and after the one or more plates have been heated to said first temperature;

using the measurement to estimate the quantity of analyte collected on the one or more plates; and

heating the one or more plates to at least a second temperature that is greater than the first temperature to cause the analyte to be released from the one or more plates.

2. A method for operating an analyte collection device as defined by claim 1

further including the step of storing the analyte on said one or more plates, wherein the controller is further programmed to perform the step of heating said one or more plates to said first temperature after said analyte has been stored on the one or more plates;

wherein said first temperature is at least about 10°

C. above ambient.

3. A method for operating an analyte collection device as defined by claim 2 and further including the step of the controller testing the analyte with an analyzer following the step of releasing the analyte.

4. A method for operating an analyte collection device as defined by claim 1, the controller further being programmed to repeat multiple iterations of the steps of heating the one or more plates to a first temperature, taking a measurement of one or more properties of the one or more plates from a detector at one or more of during the step of heating the one or more plates and after the one or more plates have been heated to said first temperature, and using the measurement to estimate the quantity of analyte collected on the one or more plates, to build a knowledge base through said iterations that is useful to predict a value for said measured property that indicates sufficient analyte has been collected for testing.

5. A method for operating an analyte collection device as defined by claim 4, the controller further being programmed to perform the method steps of storing said measured one or more properties, and storing an indication of whether sufficient analyte had been collected for testing during each of said iterations.

6. A method for operating an analyte collection device as defined by claim 2 wherein:

said one or more plates comprises a plurality of plates organized in a stacked configuration, a sorbent covering at least a portion of each of said plates;

wherein the step of storing the analyte on said one or more plates further comprises causing a fluid containing the analyte to flow past said plurality of stacked plates whereby said fluid contacts said sorbent and the analyte is absorbed by said sorbent.

7. A method for operating an analyte collection device as defined by claim 1, the controller further being programmed to perform the method the step of estimating the amount of contaminant on said one or more plates;

wherein said first temperature is higher than a desorbing temperature for the analyte.

8. A method for operating an analyte collection device as defined by claim 1 wherein said measurement comprises a first measurement, the controller further being programmed to perform the preliminary steps of heating said one or more plates to a third temperature, taking a calibration measurement of said one or more properties of said one or more plates from the detector, and comparing said first measurement to said calibration measurement to estimate the quanity of said analyte.

9. A method for operating an analyte collection device as defined by claim 1, the controller further being programmed to perform the method step of measuring the temperature of said one or more plates from the detector as said one or more plates cool from said first temperature.

10. A method for operating an analyte collection device as defined by claim 1, the controller further being programmed to perform the step of taking said measurement while said one or more plates is being heated to said first temperature.

11. A method for operating an analyte collection device as defined by claim 1, wherein the controller is programmed to measure one or more of a thermal property and an electrical property of said one or more plates from the detector.

12. A method for operating an analyte collection device as defined by claim 1, the controller further being programmed to perform the method step of determining the thermal time constant T₁ for said one or more plates using the relationship:

13. An analyte collection device, the device comprising:

one or more plates;

a heating element for heating said one or more plates;

a detector for detecting one or more properties of said one or more plates; and

,

a controller linked to said heating element, said controller including a processor, a memory, and program instructions configuring the controller to heat said heating element to a first temperature and to measure said one or more properties of said at least one or more plates using said detector, and to use said one or more properties to estimate the quantity of analyte collected on said one or more plates, said controller further including program instructions for configuring the controller to heat said at least one or more plates to at least a second temperature that is greater than said first temperature to cause said analyte to be released from said one or more plates.

14. The device of claim 13, wherein said heating element comprises a resistive trace formed on or within said at least one or more plates, wherein said plates each have a sorbent layer thereon and wherein said one or more plates comprises a plurality of plates arranged in a stacked configuration.

15. The device of claim 13, wherein:

said heating element comprises a plurality of resistive traces formed on or within said one or more plates;

said resistive traces divide said one or more plates into a plurality of zones, one of said zones being a collection zone for collecting analyte, and another being a smaller delivery zone for concentrating analyte from the collection zone in a smaller area and delivering analyte to a detector system; and

,

said controller further including program instructions for configuring the controller to control each of said zones independently from others of said zones.

16. The device of claim 13 wherein said controller further includes program instructions for configuring the controller to:

perform a calibration by heating said one or more plates to an elevated temperature when no analyte is present and to measure at least one calibration property of said one or more plates using said detector; and

,

heat said one or more plates to a third temperature greater than said second temperature, to measure a second property of said one or more plates using said detector, and to compare said second property to said calibration value to determine if a contaminant is present on said one or more plates.

17. The device of claim 13 wherein said controller further includes program instructions for configuring said controller to store in said memory said measured property together with data indicating whether sufficient material was present to perform a test, and wherein said controller further includes program instructions for configuring said controller to use said stored data to build a knowledge base over multiple tests useful to predict a minimum value for said property that indicates a sufficient quantity of said analyte is present to proceed with testing.

18. A computer program product including computer readable instructions stored on a memory medium, the program product for use with a collector device of the type that includes one or more plates for collecting analyte, a heating element for heating the one or more plates, a detector for detecting one or more properties of the one or more plates, and a controller comprising one or more computers having a processor linked to the heating element, the analyte being released when the collector device heats the plate to a desorbing temperature, wherein said controller is configured to:

cause the one or more plates to be heated to an elevated temperature that is substantially below the desorbing temperature;

measure one or more properties of the one or more plates using the detector;

use the measured one or more properties to estimate the quantity of analyte collected on the one or more plates; and

heat the one or more plates to at least a second temperature that is greater than the elevated temperature to cause the analyte to be released from the one or more plates,

when the instructions are executed by the one or more computers.

19. A computer program product as defined by claim 18 wherein said controller is further configured to perform a calibration through the steps of:

heating said plates to a first elevated temperature before analyte is stored thereon;

measuring a calibration property of said plates;

storing said calibration property in a memory;

when the instructions are executed, and

wherein the instructions when causing the collector device to determine whether sufficient analyte has been collected cause the collector device to compare the measured property to the calibration property.

20. A computer program product as defined by claim 19 wherein said controller is further configured to measure a contamination property of said plates using the detector, and to compare said contamination property to said calibration property to determine if contaminant is present on said plates, when the instructions are executed.