Needleless injector
AssigneeZogenix, Inc.
InventorTerry GREEN
Life of this patent
Estimating the term…
Abstract
A needleless injector has a syringe body having an opening at one end, a piston housed within the syringe body for urging a liquid within the syringe body through the opening and a ram for driving the piston. A shock absorbing component is provided for reducing an initial transfer of force from the ram to the piston. The initial rate of pressure increase on the liquid is reduced, thereby controlling the rate of collapse of gas bubbles in the liquid.
Claims20
1-18. (canceled)
A method of delivering liquid from a needleless injector syringe which comprises a piston housed within a syringe body and a ram for driving the piston thereby causing liquid to be driven out of the syringe, the method comprising:
- applying an initial force to the ram to initiate delivery of the liquid and collapse of a bubble in the liquid;
- during a first stage of the delivery, applying a reduced force to the piston thereby causing the bubble to collapse in a slow, controlled manner;
- and
- during a subsequent stage of the delivery, transferring substantially the full energy of the ram to the piston.
A method of preventing a collapsing bubble in a liquid formulation from causing a needle free injector capsule to break, comprising the step of causing the bubble to collapse in a slower, controlled manner immediately prior to the normal injection cycle.
A method of delivering liquid from a needleless injector syringe which comprises a piston housed within a syringe body and a ram for driving the piston thereby causing liquid to be driven out of the syringe, the method comprising:
- during a first stage of the delivery, applying a reduced force to the piston;
- and
- during a subsequent stage of the delivery, transferring substantially the full energy of to the ram to the piston.
A method of reducing the propensity for a shock wave created from the rapid collapse of a gas bubble to break an injector syringe which comprises a piston housed within a syringe body and a ram for driving the piston thereby causing liquid to be driven out of the syringe, the method comprising:
- applying an initial force to the ram, during a first stage of the delivery, applying a reduced force to the piston thereby causing the bubble to collapse in a slow, controlled manner;
- and
- during a subsequent stage of the delivery, transferring substantially the full energy of the ram to the piston.
Dependencies are inferred from the claim text.