Patent ID: 8827980

Claim:
A method of delivering dry powder to an internal operation site of beings, comprising the steps of: (a) extending a distal end of an elongated tubular delivery channel to a position that an emitting opening of said delivery channel is adjacent to said internal operation site; (b) producing pressurized gas and mixing said pressurized gas with dry powder to form a mixture of dry powder and pressurized gas in a gas powder chamber communicating with a feeding opening of said delivery channel; (c) feeding said mixture of dry powder and pressurized gas from said gas powder chamber into said delivery channel until a predetermined amount of said mixture of dry powder and pressurized gas sprays out from said emitting opening of said delivery channel for application onto said internal operation site, after the step (a), further comprising a step of generating a maintaining gas flow to said delivery channel via a gas source so as to prevent reflux of gas and fluid into said delivery channel, wherein said maintaining gas flow is generated to said delivery channel through a connecting channel which is communicatively linked from a dry powder outlet of said gas powder chamber to said feeding opening of said delivery channel, wherein the step (b) further comprises a step of generating a working as flow via said pressurized gas to deliver said dry powder into said gas powder chamber so as to emit said dry powder via said emitting opening of said delivery channel, wherein said maintaining gas flow is generated before said working gas flow is generated, wherein said maintaining gas flow and said working gas flow are generated by said gas source; (d) communicatively extending a maintaining gas flow channel from said gas source to said connecting channel for guiding said maintaining gas flow to said delivery channel; (e) providing a maintaining gas flow switch at said maintaining gas flow channel to selectively switch on-and-off said maintaining gas flow channel; (f) communicatively extending a working gas flow channel from said gas source to said dry powder inlet of said gas powder chamber for guiding said working gas flow to said delivery channel; and (g) providing a working gas flow switch at said working gas flow channel to selectively switch on-and-off said working gas flow channel.