Devices, Methods, and Systems for Collection of Volatile Organic Compounds

Abstract

A system comprises a mouth piece to receive exhaled air; a breath chamber to receive exhaled air; a valve to direct exhaled air along a desired flow path, direct purge gas along a desired flow path, control the rate of flow of purge gas, control the rate of flow of exhaled air, block the flow of purge gas, and/or block the flow of exhaled air; a source of purge gas; a CO2 cartridge to remove CO2; a water cartridge to remove water; a breath cartridge to capture VOCs from exhaled air; a temperature control system to control the temperature of CO2 cartridge, a water cartridge, and/or a breath cartridge; a cryostat to contain and limit heat flow to a cryogenic liquid; a flow meter designed to measure the flow of exhaled air and/or purge gas; and a pressure transducer to measure a pressure, a flow rate, and/or a flow volume.

1 . A system for diagnosing disease using exhaled breath, the system comprising elements selected from:
 a mouth piece configured to seal to the lips of a subject and receive exhaled air from a subject;   a breath chamber configured to receive exhaled air from the mouth piece;   a valve configured to do one or more of: direct exhaled air along a desired flow path, direct purge gas along a desired flow path, control the rate of flow of purge gas, control the rate of flow of exhaled air, block the flow of purge gas, block the flow of exhaled air;   a source of purge gas;   a CO2 cartridge configured to removed CO2 from exhaled air;   a water cartridge configured to remove water from exhaled air;   a breath cartridge configured to capture one or more VOCs from exhaled air;   a temperature control system configured to control the temperature of one or more of: a CO2 cartridge, a water cartridge, a breath cartridge;   a cryostat configured to contain and limit heat flow to a cryogenic liquid;   a flow meter designed to measure the flow of one or both of: exhaled air, purge gas; and   a pressure transducer designed to measure one of: a pressure, a flow rate, a flow volume.   
     
     
         2 . The system of  claim 1 , further comprising at least one of a mouthpiece, a breath chamber, a breath cartridge, and a cooling system, wherein the cooling system comprises LN2. 
     
     
         3 . The system of  claim 2 , wherein the subject exhales breath through the mouthpiece and breath chamber, and wherein the system further comprises valves to direct the exhaled breath through the breath cartridge when the subject is not exhaling. 
     
     
         4 . The system of  claim 3 , wherein at least 50% of the breath cartridge is submerged in LN2. 
     
     
         5 . The system of  claim 4 , wherein the breath cartridge comprises one or more channels. 
     
     
         6 . The system of  claim 5 , wherein the breath chamber has a volume of less than or about 0.5 liter. 
     
     
         7 . The system of  claim 6 , wherein the subject only exhales though the mouthpiece and breath chamber once. 
     
     
         8 . The system of  claim 6 , further comprising a source of purge gas, and further comprises two or more elements that allow for the simultaneous control of the gauge pressure in the breath cartridge and the flow through the breath cartridge, wherein the two or more elements are selected from the list consisting of:
 a flow restriction;   a pressure regulator;   a flow controller; and   a needle valve.   
     
     
         9 . The system of  claim 8 , wherein the gauge pressure in the breath cartridge is greater than 2 kPa. 
     
     
         10 . The system of  claim 9 , wherein the flow rate exiting the system is less than or about 0.5 liters per minute. 
     
     
         11 . The system of  claim 10 , wherein given the molecular weight m of a VOC of interest, the combined length L of the one or more channels and the total flow rate at room temperature Q of the air flowing through the breath cartridge satisfy the relationship:
     L /( m   0.5   Q )> C      wherein Lis in cm, m is in atomic mass units, Q is in liters per minute, and C=1.5.   
     
     
         12 . The system of  claim 11 , wherein C=6. 
     
     
         13 . The system of  claim 11 , wherein C=8. 
     
     
         14 . The system of  claim 11 , wherein C=13. 
     
     
         15 . The system of  claim 11 , further comprising a water cartridge in series with the breath cartridge, wherein the breath cartridge has a combined total channel length of L′ and it is run at a temperature T, wherein T, L′, and Q satisfy the relationship
     L*T   1.5 /( Q* 10000)> C    
 wherein Q is in liters per minute, T is in Kelvin, L is in cm, and C=5. 
 
     
     
         16 - 18 . (canceled) 
     
     
         19 . The system of  claim 6 , wherein when the subject exhales into the mouthpiece and breath chamber, the mouth piece and breath chamber are separated from the breath cartridge and LN2, and subsequently the breath chamber is integrated with the breath cartridge and LN2. 
     
     
         20 . The system of  claim 19 , wherein the mouthpiece and breath chamber assembly have elements selected from:
 an electrically activated valve;   2 or more electrically activated valves;   an electronic pressure transducer; and   a display.   
     
     
         21 . The system of  claim 19 , wherein the mouthpiece and breath chamber assembly is all mechanical with no electrical parts. 
     
     
         22 . The system of  claim 21 , wherein the breath chamber has check valves on its inlet and outlet, further wherein the check valves have a cracking pressure of greater than 0.25 kPa and less than 10 kPa. 
     
     
         23 . The system of  claim 4 , wherein the end of the breath chamber that is not submerged in LN2 is held at a temperature of about −100° C. or higher.