Apparatus and method for delivery of an aerosol
An apparatus for measuring lung ventilation, comprising: a pressure device to measure volume of air flow; an aerosol-generating device that provides aerosol particles to be released at a determined point in a breathing cycle; a mouthpiece with a detector that measures the concentration of aerosol particles for a given volume during the breathing cycle; and a computing device configured to provide lung ventilation data as a function of time constants.
1. A method for estimating aerosol particle concentrations, comprising:
introducing an aerosol bolus produced by an aerosol generator at a predetermined point in a breathing cycle;
measuring inhaled and exhaled aerosol concentrations at discrete values of at least one of time, volume and dimensionless volume;
estimating, with a computing device, initial values for intrinsic mixing on inhalation, intrinsic mixing on exhalation, effective volume of lung on inhalation, and effective volume of lung on exhalation;
minimizing the estimated initial values;
determining a volume of penetration;
estimating, with a computing device, inhaled aerosol concentration as a function of the measured inhaled aerosol concentration and at least one of K(V) and K(t), wherein K(V) is a system function for mixing in the pre-lung as a function of volume and K(t) is a system function for mixing in the pre-lung as a function of time; and
estimating, with a computing device, exhaled particle concentration as a function of the estimated inhaled aerosol concentration and a probability that a particle exits the lung in a provided volume.
2. The method of claim 1 , wherein measuring inhaled and exhaled aerosol concentrations is performed using discrete values of at least one of time, volumes and dimensionless volumes.
3. The method of claim 1 , wherein estimating initial values is performed using a minimum least squares criterion.
4. The method of claim 1 , further comprises measuring breath holding time and the effect of breath holding time on the particle concentration that is exhaled, said particle concentration being described as a percentage of the inhaled concentration as a function of the volume of penetration of the aerosol.
5. The method of claim 1 , further comprises determining a total amount or percentage of a total amount of inhaled particulate material that is exhaled during a breath or in subsequent breaths after a breath in which the aerosol is inhaled.
6. The method of claim 1 , wherein the aerosol particles are selected from one or more natural oils, one or more synthetic oils, or a blend of one or more natural and synthetic oils.
7. The method of claim 1 , further comprises determining the retention of aerosol inhaled in a single breath and exhaled over the course of subsequent breaths as a diagnostic indicator of asthma.
8. An apparatus for estimating aerosol particle concentrations, comprising:
means for measuring inhaled and exhaled aerosol concentrations at discrete values of at least one of time, volume and dimensionless volume;
means for estimating initial values for intrinsic mixing on inhalation, intrinsic mixing on exhalation, effective volume of lung on inhalation, and effective volume of lung on exhalation;
means for minimizing the estimated initial values;
means for determining a volume of penetration;
means for estimating inhaled aerosol concentration as a function of the measured inhaled aerosol concentration and at least one of K(V) and K(t), wherein K(V) is a system function for mixing in the pre-lung as a function of volume and K(t) is a system function for mixing in the pre-lung as a function of time; and
means for estimating exhaled particle concentration as a function of the estimated inhaled aerosol concentration and a probability that a particle exits the lung in a provided volume.
9. The apparatus of claim 8 , wherein the means for measuring inhaled and exhaled aerosol concentrations uses discrete values of at least one of time, volumes and dimensionless volumes.
10. The apparatus of claim 8 , wherein the means for estimating initial values uses a minimum least squares criterion.
11. The apparatus of claim 8 , further comprising means for measuring breath holding time and the effect of breath holding time on the particle concentration that is exhaled, said particle concentration being described as a percentage of the inhaled concentration as a function of the volume of penetration of the aerosol.
12. The apparatus of claim 8 , further comprising means for determining a total amount or percentage of a total amount of inhaled particulate material that is exhaled during a breath or in subsequent breaths after a breath in which the aerosol is inhaled.
13. The apparatus of claim 8 , wherein the aerosol particles are selected from one or more natural oils, one or more synthetic oils, or a blend of one or more natural and synthetic oils.
14. The apparatus of claim 8 , further comprising means for determining the retention of aerosol inhaled in a single breath and exhaled over the course of subsequent breaths as a diagnostic indicator of asthma.