Patent ID: 7806867
Filing Date: 2010-10-05
Classification: A61M

Abstract:
1. An injection device for fluid injection into a body comprising: a housing having a proximal end and a distal end, the housing having an opening proximate the distal end, the opening configured to deliver a fluid; a fluid chamber disposed inside the housing and configured to contain the fluid; a propellant chamber disposed inside the housing and spaced from the distal end of the housing; a sleeve having a proximal end and a distal end, the sleeve disposed inside the housing between the distal end of the housing and the propellant chamber, the sleeve having a first cavity in fluid communication with the propellant chamber, and having an opening between the proximal end of the sleeve and the distal end of the sleeve; and a piston mounted on the sleeve and having a proximal end and a distal end and having an opening between the proximal end of the piston and the distal end of the piston, the piston being coupled to the sleeve and having a second cavity, the piston being movable with respect to the sleeve from a first position to a second position, wherein, during use, a fluid is released from the propellant chamber causing the piston to slide over a surface of the sleeve from the first position to the second position, movement of the piston causing the fluid in the fluid chamber to be ejected through the housing opening, and wherein as the piston slides over the sleeve, the opening of the piston aligns with the opening of sleeve such that at least some of the fluid from the propellant chamber travels through the aligned openings of the sleeve and piston.