Syringe with a damping and pressure measuring device integrated in the piston and method for uniform and pressure-controlled injection by means of this syringe

摘要

A process and device for pressure-controlled manipulation of a fluid (4a), in particular for medicinal applications. The device comprises a receptacle (1a) of variable volume to contain the fluid (4a), a pressure creation device (2a) for producing pressure on the fluid (4a), an opening (1c) for admitting and/or discharging the fluid (4a), a measuring channel (2e) of prescribed cross-section connected to the receptacle (1a), and a buffer (2d) of prescribed volume which communicates with the measuring channel (2e), the measuring channel (2e) and the buffer (2d) being filled with a compressible medium. The pressure creation device is preferably a piston (2a) which can be pushed into the receptacle (1a), the piston being sealed to the inner wall of the receptacle (1a) by a sealing means (2c). According to the invention, in particular medicinal syringes are improved in that a fluid (4a) can be injected with particular evenness and at a pressure which can be precisely controlled, for example into a cavity (10) a body (9). The presssure is read or measured by determining the position of the boundary layer (8) between the fluid (4a) and the compressible medium in the measuring channel (2e), e.g. by means of a scale (2k). The size of the buffer (2d) in relation to the internal diameter of the measuring channel (2e) determines the precision of measurement and the damping properties at the time of injection.