Assay test device and method of making same

• US 20040152209A1
• Filed: 01/30/2003
• Published: 08/05/2004
• Est. Priority Date: 01/30/2003
• Status: Active Grant

• Current Assignee: Benedict L. Zin, Michael Hutchinson
• Original Assignee: Benedict L. Zin, Michael Hutchinson
• Inventors: Hutchinson, Michael, Zin, Benedict L.
• Granted Patent: US 7,220,597 B2
• Time in Patent Office: Days
• US Class Current: 436/518
• CPC Class Codes: G01N 33/523 the element being adapted for a specific analyte

Abstract

In accordance with certain disclosed embodiments of the present invention, there is provided an assay test device for determining whether a fluid under test contains a certain substance, wherein the device includes a test strip disposed at least partially within a housing for receiving the fluid under test. A sensor mounted on the housing detects the certain substance in the fluid under test received on the test strip to generate an electrical signal indicative of the amount of the substance detected. A processor responds to the signal for determining whether or not the fluid under test contains a predetermined quantity of the certain substance to generate an electric output signal. A display mounted on the housing responds to the output signal to indicate the presence or absence of a predetermined quantity of the certain substance contained within the fluid under test.

According to other embodiments of the invention, the processor delays in activating the reaction sensor until after a predetermined time delay interval. The processor stores the sensor signal at the completion of the time delay interval, and compares the stored sensor signal with stored threshold electric signals to determine whether or not the fluid under test contains a predetermined quantity of the certain substance.

Claims

1. An assay test device for determining whether a fluid under test contains a certain substance, comprising:

a housing;

an elongated test strip disposed at least partially within said housing for containing a reagent, said strip for receiving a sample of the fluid under test at one end portion thereof;

a sample sensor mounted on said housing and positioned remotely of the sample receiving end portion of said test strip for detecting the presence of the sample as it flows from the test strip end portion for generating a signal indicative of the presence of said sample;

a processor responsive to the sample presence signal for starting a timer to generate a time delay interval and for generating a time-out signal at the end of the interval;

a reaction sensor mounted on said housing and responsive to said time-out signal for detecting the certain substance in the fluid under test received on said test strip to generate an electrical signal indicative of the amount of the substance detected;

said processor being responsive to said signal from said reaction sensor for generating an output signal indicative of the presence or absence of at least a predetermined quantity of the substance contained in the sample; and

a display mounted on said housing responsive to said output signal for indicating the presence or absence of a predetermined quantity of the certain substance contained within the fluid under test.

2. An assay test device according to claim 1, wherein said test strip produces a reaction indication in the presence of the certain substance in the fluid under test.

3. An assay test device according to claim 2, wherein said reaction sensor is a photo-optic sensor to generate the electrical signal indicative of the amount of substance relative to the amount of the photoreflectance of the reaction indication.

4. An assay test device according to claim 1, wherein said processor delays in storing the reaction sensor signal until after a predetermined time delay interval.

5. An assay test device according to claim 4, wherein said processor stores the sensor signal at the completion of the time delay interval, and compares the stored sensor signal with stored threshold electric signals to determine whether or not the fluid under test contains a predetermined quantity of the certain substance.

6. An assay test device according to claim 4, wherein said test strip includes an elongated wick for receiving the fluid under test at one end portion thereof.

7. An assay test device according to claim 6, wherein the sample sensor is mounted on said housing adjacent to said wick disposed remotely of the fluid receiving end portion to detect the presence of the fluid under test to generate an electric signal indicative of the start of said predetermined time delay interval.

8. An assay test device according to claim 1, wherein said display includes a display element indicating that the device is ready to receive the fluid under test.

9. An assay test device according to claim 8, wherein said display further includes a positive substance indication display element and a negative substance indication display element.

10. An assay test device according to claim 9, wherein each of said display elements include light emitting diodes.

11. An assay test device according to claim 6, further including a lid removably attached to said housing for covering at least a portion of the fluid receiving end portion of the wick so that said lid can be removed from said housing to expose said fluid receiving end portion of the wick.

12. An assay test device according to claim 10, further including switch means for activating said device, said switch means being responsive to the removal of said lid from said housing.

13. An assay test device according to claim 12, wherein said switch means includes an insulator connected to said lid for deactivating the device, further including a battery for energizing the device, said insulator for connecting electrically the battery.

15. A method according to claim 1, further including assembling said sensors, said test strip, said processor and said display within said housing.

16. A method according to claim 15, further including replacing the test strip following a test with a fresh test strip.

17. A method according to claim 16, wherein said replacing includes disabling a housing at least partially confirming the test strip to permit it to be removed therefrom, and re-assembling the housing with the fresh test strip installed in place.

14. A method of testing a fluid to determine whether or not it contains a certain substance, comprising:

sensing the presence of a sample of the fluid under test received on a test strip;

generating a signal indicative of the presence of the sensed sample;

starting a time delay interval;

generating a time-out signal at the end of the interval;

sensing a reaction in response to said time-out signal;

determining whether or not the fluid under test contains a predetermined quantity of the certain substance using a processor;

generating an electric output signal using the processor in response to its determination; and

indicating the presence or absence of a predetermined quantity of the certain substance contained within the fluid under test.