Medical vial and injector assemblies and methods of use

Abstract

A medical liquid vial is disclosed with a resilient inner bladder and a prestress member located with the bladder. Injector assemblies are also disclosed for injecting the vial contents into a patient by advancing the vial through a series of stages or positions. Methods of filling and use are also disclosed.

What is claimed is: 
     
         1 . A medical fluid injection device that may be adhered to the skin of a patient, the device including:
 a housing including a skin-facing surface;   a medical fluid reservoir defined by an expandable elastomeric bladder that is expandable upon the pressurized introduction of medical fluid thereunto, the elastomeric bladder exerting a force on the medical fluid there within;   an injection needle including an injection end movable between a retracted position within the housing and an injection position extending through the skin facing surface of the housing for injection into a patient, the needle being in fluid communication with the bladder in the injection position; and   the skin-facing surface including a skin-facing protrusion located around the injection needle when in the injection position, said protrusion including a circumferential base portion adjacent to where the protrusion joins the skin-facing surface, said circumferential base portion tapering radially inwards towards the injection needle when the injection needle is in the injection position.   
     
     
         2 . The medical fluid injection device of  claim 1  further comprising a double-sided adhesive member adhered on one side to the skin-facing surface, the other side of the adhesive member including a removable cover that may be removed to expose adhesive for holding the medical fluid injection device on the skin of a patient. 
     
     
         3 . The medical fluid injection device of  claim 2  wherein said double-sided adhesive member also includes a bandage portion positioned over the skin-facing protrusion that remains adhered to the patient's skin upon removal of the medical fluid injection device from the patient. 
     
     
         4 . The medical fluid injection device of  claim 3  wherein an adhesion force between the bandage and the skin-facing surface is greater than an adhesion force between the bandage and the double-sided adhesive. 
     
     
         5 . The medical fluid injection device of  claim 3  wherein the injection needle pierces the bandage as the injection needle moves from the retracted position into the injection position.