US 12,220,284 B2
Color sensor with gas generating layer
Gregory Heacock, Maple Valley, WA (US)
Assigned to THERMOGRAPHIC MEASUREMENTS LIMITED, (GB)
Filed by THERMOGRAPHIC MEASUREMENTS LIMITED, Connah's Quay (GB)
Filed on Oct. 17, 2016, as Appl. No. 15/295,431.
Prior Publication US 2018/0104017 A1, Apr. 19, 2018
Int. Cl. A61B 90/00 (2016.01); G01N 21/78 (2006.01); G01N 21/80 (2006.01); G01N 31/22 (2006.01)
CPC A61B 90/08 (2016.02) [G01N 21/783 (2013.01); G01N 21/80 (2013.01); G01N 31/223 (2013.01); G01N 31/229 (2013.01); A61B 2090/081 (2016.02); G01N 31/221 (2013.01); G01N 31/225 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A color change sensor comprising:
a color change indicator for detecting an atmospheric gas, wherein the color change indicator is a dye that changes color when contacted by the atmospheric gas;
a gas-containing substrate disposed on the color change indicator, the gas-containing substrate comprising pores, matrices, or passages,
the gas-containing substrate containing non-atmospheric levels of a substrate gas dispersed in the pores, matrices, or passages to form a gas layer at the non-atmospheric levels of the substrate gas on at least a portion of the color change indicator prior to activation of the color change sensor, wherein the color change indicator does not change color when contacted by the non-atmospheric levels of the substrate gas, wherein the gas layer diffuses out of the gas-containing substrate after activation of the color change sensor to allow the atmospheric gas to reach the color change indicator, the gas layer inhibiting atmospheric levels of the atmospheric gas from contacting the color change indicator prior to activation of the color change sensor and delaying detection of the atmospheric gas by the color change indicator while the gas layer diffuses out of the gas-containing substrate; and
an interface layer inhibiting the escape of the gas layer from the gas-containing substrate prior to activation of the color change sensor, the interface layer disposed on at least a portion of the gas-containing substrate, wherein the color change sensor is activated by removing or disrupting at least a portion of the interface layer or by removing or disrupting at least a portion of the gas-containing substrate,
wherein the substrate gas is selected from the group consisting of ammonia, carbon dioxide, nitrogen, argon and/or oxygen, and the non-atmospheric levels of the substrate gas in the gas-containing substrate is different than the atmospheric levels of the atmospheric gas present in an environment surrounding the color change sensor.