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

• US 10,209,232 B2
• Filed: 12/17/2014
• Issued: 02/19/2019
• Est. Priority Date: 01/02/2014
• Status: Active Grant

• Current Assignee: Arizona Board of Regents (University of Arizona)
• Original Assignee: Arizona Board of Regents (University of Arizona)
• Inventors: Forzani, Erica, Tao, Nongjian, Zhao, Di, Tsow, Francis
• Primary Examiner(s): Sines, Brian J.
• Application Number:
  US15/104,668
• Publication Number:
  US 20160313290A1
• Time in Patent Office: 1,525 Days
• Field of Search: 422 83, 422 84, 422 85, 422 98, 436 43, 436145, 436164, 436167
• CPC Class Codes: A61B 2560/0242 adapted to measure environmental factors, e.g. temperature, pollution
• CPC Class Codes: A61B 2560/0252 using ambient temperature
• CPC Class Codes: A61B 5/0022 Monitoring a patient using a global network, e.g. telephone networks, internet
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/082 Evaluation by breath analysis, e.g. determination of the chemical composition of exhaled breath A61B5/083, A61B5/091 take precedence
• CPC Class Codes: G01N 21/8483 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 Class Codes: G01N 33/004 CO or CO2
• CPC Class Codes: G01N 33/497 of gaseous biological material, e.g. breath

Abstract

A CO₂ detection chamber includes a gas inlet and a gas outlet. A CO₂ sensor is housed in the CO₂ detection chamber, where the sensor includes a reversible and selective pH-sensitive nanocomposite sensor element for CO₂ 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 CO₂ 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 CO₂ measurements is transmitted for display to a mobile device.

Claims

1. A pocket-sized multifunctional CO₂ detector for use in predicting pulmonary disease comprising:

a non-invasive CO2 detection chamber including a gas inlet and a gas outlet;

a CO₂ sensor housed in the CO₂ 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 CO₂ 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 CO₂ 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 CO₂ 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 CO₂ detection and environmental CO₂ detection mode wherein CO₂ concentration as a function of time is plotted.

8. The detector of claim 6 where the test module comprises environmental CO₂ 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.