Aerosol And A Method And Apparatus For Generating An Aerosol

What is this patent about?

'251 is related to the field of aerosol generation, specifically addressing the limitations of existing aerosol devices that rely on compressed gas propellants or manual pumps. Traditional methods often suffer from environmental concerns (CFCs), difficulties in synchronizing inhalation with device operation, and limitations in achieving desired particle sizes for effective drug delivery to the lungs. The invention aims to provide an alternative approach that overcomes these drawbacks.

The underlying idea behind '251 is to create an aerosol by volatilizing a liquid material through heating, and then allowing it to condense into fine particles upon mixing with ambient air. This eliminates the need for compressed gas propellants. A key aspect is the use of a heated tube to achieve rapid vaporization and subsequent condensation, enabling control over particle size and flow rate.

The claims of '251 focus on an aerosol generator comprising a tube with an open end and a heater positioned to heat the tube. The claims also cover a method for generating an aerosol by supplying a liquid material to the tube, heating the tube to volatilize the material, and allowing the volatilized material to expand and condense into an aerosol upon mixing with ambient air. The claims further extend to the aerosol itself, formed by this process.

In practice, a liquid is fed into a narrow tube, and a heater, such as a resistance wire or a thin-film platinum layer, rapidly heats the tube. This causes the liquid to vaporize and expand out of the tube's open end. As the vapor mixes with the cooler surrounding air, it condenses into an aerosol of fine particles. The size of these particles can be controlled by adjusting parameters like the tube diameter, heater temperature, and liquid flow rate. The device can be configured for intermittent or continuous aerosol generation, and can be integrated with a puff-actuated sensor for on-demand drug delivery.

This approach differs from prior solutions by avoiding compressed propellants, which are environmentally harmful and can make it difficult to control particle size. Unlike manual pumps, the heating method allows for a more consistent and controllable aerosol generation. The use of a heated tube enables the creation of aerosols with very small particle sizes (less than 2 microns), facilitating deep lung penetration for drug delivery, and potentially achieving high flow rates of the aerosolized material.