PHOTO-ACOUSTIC DETECTION DEVICE AND METHOD

• US 20110217762A1
• Filed: 05/18/2011
• Published: 09/08/2011
• Est. Priority Date: 07/11/2006
• Status: Active Grant

• Current Assignee: Curators of the University of Missouri (University of Missouri)
• Original Assignee: Curators of the University of Missouri (University of Missouri)
• Inventors: Weight, Ryan M., Sutovsky, Peter, Viator, John A., Dale, Paul S.
• Granted Patent: US 8,293,176 B2
• Time in Patent Office: Days
• US Class Current: 435/287.1
• CPC Class Codes: G01N 21/1702 with opto-acoustic detection, e.g. for gases or analysing solids

Abstract

An example method for detecting an analyte in a sample of a bodily fluid comprises the steps of exposing the bodily fluid sample to electromagnetic energy to cause a thermoelastic expansion in the analyte, and detecting a photoacoustic signal in the sample that results from the thermoelastic expansion.

Claims

1. A system for detecting one or more analytes in a bodily fluid comprising:

a test chamber having at least one sidewall and configured to contain at least a portion of a bodily fluid sample;

an electromagnetic energy source configured to direct an energy source into said test chamber through said at least one sidewall and to induce a thermoelastic expansion in said one or more analytes; and

,

a sensor configured to detect said thermoelastic expansion in said bodily fluid sample in said test chamber.

2. A system as defined by claim 1 wherein said sensor comprises an acoustic sensor having a diaphragm that is deflected when an acoustic wave generated by said thermoelastic expansion strikes it, said acoustic sensor arranged on said test chamber.

3. A system as defined by claim 2 wherein said acoustic sensor diaphragm comprises a piezoelectric diaphragm in fluid contact with said test sample, wherein said acoustic sensor further comprises first and second electrodes arranged about opposing sides of said piezoelectric diaphragm.

4. A system as defined by claim 1 wherein said electromagnetic energy source comprises a laser pulsing at a frequency faster than a millisecond.

5. A system as defined by claim 1 and further comprising:

a reservoir, a conduit, and a pump, said reservoir communicating with said test chamber via said conduit, said pump arranged along said conduit to urge said sample from said reservoir to said test chamber;

wherein said electromagnetic energy source comprises a pulsed laser; and

,

wherein said test chamber at least one sidewall comprises at least a first and a second sidewall, said first sidewall being narrower than said second sidewall, said pulsed laser directed through said first sidewall and said sensor arranged on said second sidewall.

6. A system as defined by claim 1 and wherein said test chamber is transparent and wherein said electromagnetic energy source comprises a pulsed laser having a beam that illuminates an entire cross section of said test sample as it passes through said test chamber.

7. A system as defined by claim 1, wherein said excitation electromagnetic energy source is configured to direct a first energy beam having a first wavelength but not a second wavelength, and at a different time to direct a second energy beam having the second wavelength but not the first wavelength into the test chamber, the first energy beam inducing a first thermoelastic expansion in a first analyte that absorbs the first wavelength but not the second wavelength, the second beam inducing a second thermoelastic expansion in a second analyte that absorbs the second wavelength but not the first wavelength, the first and second beams extending across the entire cross sectional area of the flowing sample wherein no portion of the sample escapes illumination by the beam as it flows through the test chamber