Apparatus and method for generating and concentrating fine particle aerosols

Inventors

Yeates, Donovan B • Heng, Xin

Assignees

Kaer Biotherapeutics Corp

Abstract

A system and a method for generating a respirable dry powder aerosol (15) from a liquid solution or liquid suspension at a respirable dry powder aerosol volume flow (91). A liquid aerosol generating nozzle (3) generates from the liquid solution or liquid suspension a liquid aerosol (13) that is diluted by dilution gas (4) and dried in a cylindrical evaporation chamber (6) to generate a dry powder aerosol (14) that is subsequently concentrated by a cylindrical single linear slit aerosol concentrator (9). The system and method may include heliox as a gas, specifically dilution gas (4), for enhancing both the drying process in the cylindrical evaporation chamber (6) and for enhancing the concentration efficiency, but also as a nozzle gas (2) for enhancing generating the liquid aerosol (13) from the liquid solution or liquid suspension.

Core Innovation

The patent describes an aerosol generating system for generating a respirable dry powder aerosol from a liquid solution or liquid suspension at a respirable dry powder aerosol volume flow. The system includes a liquid aerosol generating nozzle that receives the liquid solution or liquid suspension and a nozzle gas supply, and outputs a liquid aerosol suspended in the nozzle gas. The patent further includes a cylindrical evaporation chamber connected to the nozzle output end and connected to a dilution gas supply, which outputs a first intermediate dry powder aerosol at a first intermediate dry powder aerosol volume flow and particle concentration.

The patent then provides a cylindrical single linear slit aerosol concentrator connected to the cylindrical evaporation chamber output end. The concentrator comprises a converging cylindrical single linear slit aerosol concentrator input channel that converges to an input orifice, an aerosol separation space connected to an exhaust port and to an output orifice, and a diverging cylindrical single linear slit aerosol concentrator output channel. The outputting of the respirable dry powder aerosol occurs at a lower volume flow than the first intermediate dry powder aerosol volume flow and at a higher particle concentration than the first intermediate dry powder aerosol particle concentration.

The patent describes the use of heliox (helium/oxygen) as a nozzle gas and/or dilution gas to reduce particle size and enhance evaporation and concentration efficiency. The document characterizes resulting aerosols by MMAD and reports that the generated aerosols can include medically active agent-containing respirable particles suspended in gas. The patent describes additional concentrator configurations including cylindrical radial multi-slit aerosol concentrators and two-stage combinations that include a radial multi-slit concentrator and a linear slit concentrator for higher total efficiency.

Claims Coverage

The document includes two independent claims: an aerosol generating system claim and a method claim. Both independent claims cover a multistage pathway that forms a first intermediate dry powder aerosol in a cylindrical evaporation chamber and then concentrates it in a cylindrical single linear slit aerosol concentrator to reduce volume flow while increasing particle concentration. The claims specify the gas and device architecture at the nozzle, chamber, and concentrator.

Across the independent claims, the inventive concept is the combination of producing a first intermediate dry powder aerosol in a cylindrical evaporation chamber and then concentrating it in a cylindrical single linear slit aerosol concentrator so that the respirable dry powder aerosol is output at a reduced volume flow and an increased particle concentration relative to the intermediate aerosol. The system/method further requires a nozzle that outputs a liquid aerosol suspended in nozzle gas and uses a converging/diverging single linear slit architecture with an aerosol separation space connecting to an exhaust port and an output orifice.

Stated Advantages

Documented Applications