Jet injector

A jet injector being used in mass vaccinations, 1976 swine flu outbreak, United States

A jet injector is a type of medical injecting syringe device used for a method of drug delivery known as jet injection. A narrow, high-pressure stream of liquid is made to penetrate the outermost layer of the skin (stratum corneum) to deliver medication to targeted underlying tissues of the epidermis or dermis ("cutaneous" injection, also known as classical "intradermal" injection), fat ("subcutaneous" injection), or muscle ("intramuscular" injection).

The jet stream is usually generated by the pressure of a piston in an enclosed liquid-filled chamber. The piston is usually pushed by the release of a compressed metal spring, although devices being studied may use piezoelectric effects and other novel technologies to pressurize the liquid in the chamber. The springs of currently marketed and historical devices may be compressed by operator muscle power, hydraulic fluid, built-in battery-operated motors, compressed air or gas, and other means. Gas-powered and hydraulically powered devices may involve hoses that carry compressed gas or hydraulic fluid from separate cylinders of gas, electric air pumps, foot-pedal pumps, or other components to reduce the size and weight of the hand-held part of the system and to allow faster and less-tiring methods to perform numerous consecutive vaccinations.

Jet injectors were used for mass vaccination, and as an alternative to needle syringes for diabetics to inject insulin. However, the World Health Organization no longer recommends jet injectors for vaccination due to risks of disease transmission.[1] Similar devices are used in other industries to inject grease or other fluid.

The term "hypospray", although better known within science fiction, originates from a jet injector known as the Hypospray; it has been cited within several scientific articles.[2][3][4]

  1. ^ Cite error: The named reference who was invoked but never defined (see the help page).
  2. ^ Clarke AK, Woodland J (February 1975). "Comparison of two steroid preparations used to treat tennis elbow, using the hypospray". Rheumatol Rehabil. 14 (1): 47–9. doi:10.1093/rheumatology/14.1.47. PMID 1091959.
  3. ^ Hughes GR (June 1969). "The use of the hypospray in the treatment of minor orthopaedic conditions". Proc. R. Soc. Med. 62 (6): 577. PMC 1811070. PMID 5802730.
  4. ^ Baum J, Ziff M (March 1967). "Use of the hypospray jet injector for intra-articular injection". Ann. Rheum. Dis. 26 (2): 143–5. doi:10.1136/ard.26.2.143. PMC 1031030. PMID 6023696.