Specific, reversible, and wide-dynamic range sensor for real time detection of carbon dioxide

Patent metadata

Field	Value
Publication number	US-10209232-B2
Application number	US-201415104668-A
Country	US
Kind code	B2
Filing date	Dec 17, 2014
Priority date	Jan 2, 2014
Publication date	Feb 19, 2019
Grant date	Feb 19, 2019

Abstract

A CO 2 detection chamber includes a gas inlet and a gas outlet. A CO 2 sensor is housed in the CO 2 detection chamber, where the sensor includes a reversible and selective pH-sensitive nanocomposite sensor element for CO 2 detection, and a hydrophobic surface. A flowmeter, a thermistor and a humidity sensor operate to read flow and compensate for humidity conditions. A light source is coupled to receive signals from the CO 2 sensor and respond to color changes in the sensor by transducing the color change into a light intensity change. A photodiode receives signals from the light source and responds to light intensity changes by transducing the light intensity changes into electronic signals representing varying degrees of light intensity. Data representing CO 2 measurements is transmitted for display to a mobile device.

First claim

What is claimed is:

1. A pocket-sized multifunctional CO 2 detector for use in predicting pulmonary disease comprising:
a non-invasive CO2 detection chamber including a gas inlet and a gas outlet;
a CO 2 sensor housed in the CO 2 detection chamber in direct fluid communication with the gas inlet, where the sensor includes a reversible and selective pH-sensitive nanocomposite sensor element including m-cresol purple, thymol blue, or bromothymol blue for CO 2 detection, and a porous hydrophobic surface with microstructures, wherein the porous hydrophobic surface includes a plurality of microstructures made of fluorinated polymers or fluorinated surfaces that have large surface-to-volume ratio providing dense reactive sites to promote the formation of nano-sized reaction clusters;
a flowmeter;
a thermistor;
a humidity sensor;
at least one light source coupled to receive signals from the CO 2 sensor and respond to color changes in the sensor by transducing the color change into a light intensity change;
at least one photodiode coupled to receive signals from the at least one light source and which responds to light intensity changes by transducing the light intensity changes into electronic signals representing varying degrees of light intensity;
a power source coupled to power the CO 2 detector elements; and
a microcontroller electronically coupled to the flowmeter, thermistor, the humidity sensor and the photodiode.

2. The detector of claim 1 further comprising:
a transmitter; and
a mobile device coupled to receive data transmitted by the transmitter.

3. The detector of claim 2 wherein the transmitter includes an antenna for wireless transmission of data.

4. The detector of claim 2 wherein the mobile device comprises a user interface including a display screen.

5. The detector of claim 2 wherein the mobile device comprises:
a computer application residing in the mobile device or accessible thereby to control the user interface and provide the real-time data display, storage, and transmission of data transmitted from the detector.

6. The detector of claim 5 wherein the computer application comprises:
a user profile module;
a test module; and
a history module, where the modules operate and respond to inputs from the user interface.

7. The detector of claim 6 where the test module comprises a breath CO 2 detection and environmental CO 2 detection mode wherein CO 2 concentration as a function of time is plotted.

8. The detector of claim 6 where the test module comprises environmental CO 2 detection.

9. The detector of claim 1 wherein the porous hydrophobic surface is coated with sensing chemicals affixed to a sensor cartridge.

10. The detector of claim 9 wherein the nano-sized reaction clusters include hydrophilic pH-sensitive molecular probes.

11. The detector of claim 10 wherein the hydrophilic pH-sensitive molecular probes comprise a pH indicator, an amine buffer and phase transfer agents.

Assignees

• Univ Arizona State

Inventors

• Forzani Erica
• Tao Nongjian
• Zhao Di
• Tsow Francis

Classifications

• G01N21/8483

  Investigating reagent band (test-element handling not specific to a test method G01N33/4875; analytical elements specific to chemical analysis of biological material G01N33/52; autometer with reagent band G01N35/04) · CPC title

• A61B5/0059

  using light, e.g. diagnosis by transillumination, diascopy, fluorescence (photoacoustic A61B5/0093; optical measurement of heart rate A61B5/02416; optical measurement of blood flow A61B5/0261; optical measurement of analytes A61B5/1455) · CPC title

• G01N33/004 Primary

  CO or CO2 · CPC title

• A61B5/082

  Evaluation by breath analysis, e.g. determination of the chemical composition of exhaled breath (A61B5/083, A61B5/091 take precedence) · CPC title

• G01N33/497

  of gaseous biological material, e.g. breath · CPC title