Patent attributes
An improved carbon dioxide absorber for use in a closed circuit patient breathing system has a canister insertable in the breathing circuit for receiving recirculating breathing gases. The canister contains a pelletized CO2 absorbent material that removes the CO2 from the breathing gases passing through the absorber. A quantity of the CO2 absorbent material is treated with a chemical indicator such that the chemical indicator makes a color change indicative of the state of the absorptive capacity of the absorbent material. A separate quantity of the CO2 absorbent material is treated with a second chemical indicator. The second chemical indicator changes color to indicate the degree of dryness of the CO2 absorbent material. The second chemical indicator may comprise cobalt chloride and serves to indicate the potential for excessive heat generation and toxic gas generation conditions within the CO2 absorbent canister.
