Assisted manual injector devices and methods

摘要: Various embodiments disclosed herein relate to needle-based injectors that incorporate a power assembly comprising stored energy source and rate control assembly. The may be further configured allow the injection performed with more force than user capable of delivering, while also allowing maintain process after has been released begun, such increase or decrease injection, stop during process. In various embodiments, comprise spring- gas-based sources, and/or friction- tension-based assemblies. Described are methods for injecting an agent using devices described here.