| 摘要 |
The spacer, which is for attachment to the mouthpiece of a dry powder inhaler or pressurised MDI, has its own mouthpiece formation at the end remote from attachment and is associated with means for producing a pressure difference within the inhaler/spacer combination relative to ambient air pressure so as to generate a flow of air through the inhaler and achieve effective dose dispersion and delivery. Negative pressure may be generated inside the combination by expanding a transparent bellows which itself forms the spacer or the spacer volume may be changed by means of a piston/seal arrangement or deformable diaphragm. Alternatively, a vacuum chamber or store of pressurised gas may be used to produce the pressure difference. |
