A jet injector is a type of medical injecting syringe that uses a high-pressure narrow jet of the injection liquid instead of a hypodermic needle to penetrate the epidermis. It is powered by compressed air or gas, either from a pressure hose from a large cylinder, or from a built-in gas cartridge, small cylinder, or spring (as in the MadaJet, Medijector Vision, Vitajet, Injex 23 and 30, or Insujet).
Jet injectors were used for mass vaccination, and as an alternative to needle syringes for diabetics to inject insulin. As well as health uses, similar devices are used in other industries to inject grease or other fluid.
The term "hypospray," although better known within science-fiction, originates from an actual jet injector known as the Hypospray and has been cited within several scientific articles.
Video Jet injector
Types
A jet injector, also known as a jet gun injector, air gun, or pneumatic injector, is a medical instrument that uses a high-pressure jet of liquid medicament to penetrate the skin and deliver and deposit medicament under the skin, without a needle. Jet injectors can be single-dose or multi-dose jet injectors.
Throughout the years jet injectors have been redesigned to overcome the risk of carrying contamination to subsequent subjects.
To try to stop the risk, researchers placed a single-use protective cap over the reusable nozzle. The protective cap was intended to act as a shield between the reusable nozzle and the patient's skin. After each injection the cap would be discarded and replaced with a sterile one. These devices were known as protector cap needle-free injectors or PCNFI.
However, a safety-test by Kelly and colleagues (2008) found a PCNFI device failed to prevent contamination. After administering injections to Hepatitis B patients, researchers found Hepatitis B had penetrated the protective cap and contaminated the internal components of the jet injector, showing that the internal fluid pathway and patient contacting parts cannot safely be reused.
Researchers developed a new jet injection design by combining the drug reservoir, plunger and nozzle into a single-use disposable cartridge. The cartridge is placed onto the tip of the jet injector and when activated a rod pushes the plunger forward. These devices are known as disposable-cartridge jet injectors or DCJI.
The International Standards Organization recommended abandoning the use of the name "jet injector" which is associated with carrying a risk of cross-contamination and rather refer to newer devices as "needle-free injectors."
Modern needle-free injector brands
The Biojector 2000 is a make of gas-cartridge-powered jet injector. It is claimed by its manufacturer that it can deliver intramuscular injections and subcutaneous injections up to 1 milliliter. The part which touches the patient's skin is single-use and can be replaced easily. It can be powered from a big compressed gas cylinder instead of gas cartridges. It is made by Bioject.
The Vision (MJ7) is a compact, spring-powered jet injector. It can deliver up to 1.6ml in 0.03ml increments, and is designed to last 3000 injections. The medication travels through a hole in the needle-free syringe that is about half the diameter of a 30 gauge syringe. The part which touches the patient's skin can be used for a week. The device was designed by Antares Pharma (formerly Medi-Jector).
The PharmaJet Needle-Free Injector delivers vaccines either intramuscularly or subcutaneously by means of a narrow, precise fluid stream syringe that delivers the medicine or vaccine through the skin in one-tenth of a second.
Diabetics have been using jet injectors in the United States for at least 20 years. These devices have all been spring loaded. At their peak, jet injectors accounted for only 7% of the injector market. Currently, the only model available in the United States is the Injex 23. In the United Kingdom, the Insujet has recently entered the market. As of June 2015, the Insujet is available in the UK and a few select countries.
Maps Jet injector
Concerns
Since the jet injector breaks the barrier of the skin, there is a risk of blood and biological material being transferred from one user to the next. Research on the risks of cross-contamination arose immediately after the invention of jet injection technology.
There are three types of inherent problems with jet injectors:
Splash-back
Splash-back refers to the jet stream penetrating the outer skin at a high velocity causing the jet stream to ricochet backwards and contaminate the nozzle.
Instances of splash-back have been published by several researchers. Samir Mitragrotri visually captured splash-back after discharging a multi-use nozzle jet injector using high-speed microcinematography. Hoffman and colleagues (2001) also observed the nozzle and internal fluid pathway of the jet injector becoming contaminated.
Fluid suck-back
Fluid suck-back occurs when blood left on the nozzle of the jet injector is sucked back into the injector orifice, contaminating the next dose to be fired.
The CDC has acknowledged that the most widely used jet injector in the world, the Ped-O-Jet, sucked fluid back into the gun. "After injections, they [CDC] observed fluid remaining on the Ped-O-Jet nozzle being sucked back into the device upon its cocking and refilling for the next injection (beyond the reach of alcohol swabbing or acetone swabbing)," stated Dr. Bruce Weniger.
Retrograde flow
Retrograde flow happens after the jet stream penetrates the skin and creates a hole, if the pressure of the jet stream causes the spray, after mixing with tissue fluids and blood, to rebound back out of the hole, against the incoming jet stream and back into the nozzle orifice.
This problem has been reported by numerous researcher.
Hepatitis B can be transmitted by less than one millionth of a millilitre so makers of injectors must ensure there is no cross-contamination between applications. The World Health Organization no longer recommends jet injectors for vaccination due to risks of disease transmission.
Numerous studies have found cross-infection of diseases from jet injections. An experiment using mice, published in 1985, showed that jet injectors would frequently transmit the viral infection LDV from one mouse to another. Another study used the device on a calf, then tested the fluid remaining in the injector for blood. Every injector they tested had detectable blood in a quantity sufficient to pass on a virus such as hepatitis B.
From 1984-1985 a weight-loss clinic in Los Angeles, California administered human chorionic gonadotropin with a Med-E-Jet injector. CDC investigation found 57 out of 239 people who had received the jet injection tested positive for hepatitis B.
In addition to transmission between patients, jet injectors have been found to inoculate bacteria from the environment into users. In 1988 a podiatry clinic used a jet injector to deliver local anaesthetic into patients' toes. Eight of these patients developed infections caused by Mycobacterium chelonae. The injector was stored in a container of water and disinfectant between use, but the organism grew in the container. This species of bacteria is sometimes found in tap water, and had been previously associated with infections from jet injectors.
History
- December 18, 1866: Jules-Auguste Béclard presents Dr. Jean Sales-Girons invention, Appareil pour l'aquapuncture to l'Académie Impériale de Médecine in Paris. This is the earliest documented jet injector to administer water or medicine under enough pressure to penetrate the skin without the use of a needle.
- 1920s: Diesel engines begin to be made in large quantities: thus the start of serious risk of accidental jet-injection by their fuel injectors in workshop accidents.
- 1935: Arnold K. Sutermeister, a mechanical engineer, witnessed a worker injure his hand from a high pressure jet stream and theorizes of using the concept to administer medicine. Sutermeister collaborates with Dr. John Roberts in creating a prototype jet injector.
- 1937: First published accidental jet injection by a diesel engine's fuel injector.
- 1936: Marshall Lockhart, an engineer, files a patent for his idea of a jet injector after learning of Sutermeister's invention.
- 1947: Lockhart's jet injector, known as the Hypospray, was introduced for clinical evaluation by Dr. Robert Hingson and Dr. James Hughes.
- 1951: The Commission on Immunization of the Armed Forces Epidemiological Board requested the Army Medical Service Graduate School to develop "jet injection equipment specifically intended for rapid semiautomatic operation in large-scale immunization programs." This device would become known as the multi-use nozzle jet injector (MUNJI).
- 1954-1967: Dr. Robert Hingson partook in numerous health expeditions with his charity Brother's Brother Foundation. Hingson stated he vaccinated upwards of 2 million people across the globe using various multi-use nozzle jet injectors.
- 1955: Warren and colleagues (1955) reported on the introduction of a prototype multi-dose jet injector, known as the Press-O-Jet, which had successfully undergone clinical testing upon 1,685 soldiers within the U.S. Army.
- 1959: Abram Benenson, the Lieutenant Colonel for the Division of Immunology at Walter Reed Army Institute of Research reports on the development of what became widely known as the Ped-O-Jet. The invention was the collaboration of Dr. Benenson and Aaron Ismach. Ismach was a civilian scientist working for the US Army Medical Equipment and Research Development Laboratory.
- 1961: The Department of the Army made multi-use nozzle jet injectors the standard for administering immunizations.
- 1961: The CDC implemented mass vaccination programs across the United States called Babies and Breadwinners to combat polio. These vaccination events used multi-use nozzle jet injectors.
- 1964: Aaron Ismach invents an intradermal nozzle for the Ped-O-Jet injector, which allowed to deliver the shallower smallpox vaccinations.
- 1964: Aaron Ismach was awadred the Exceptional Civilian Service Award at the Eighth Annual Secretary of the Army Awards ceremonies for his invention of the intradermal nozzle.
- 1966: Oscar Banker, an engineer, patents his invention of a portable multi-use nozzle jet injector that utilizes CO2 as its energy source. This would become known as the Med-E-Jet.
- September 1966: The Star Trek series started to use its own jet injector device under the name "hypospray".
- 1967: Nicaraguans undergoing smallpox vaccinations nicknamed the gun-like jet injectors (Ped-O-Jet and Med-E-Jet) as "la pistola de la paz", meaning "the pistol of peace". The name "Peace Guns" stuck.
- 1976: The United States Agency for International Development (USAID) published a book called War on Hunger which detailed the War Against Smallpox which Ismach's Jet Injector gun was used to eradicate the disease in Africa and Asia. The US government spent $150 million a year to prevent its recurrence in North America.
- 1986: A hepatitis B outbreak occurs amongst 57 patients at a Los Angeles clinic due to a Med-E-Jet injector.
- 1997: The US Department of Defense, the jet injector's biggest user, announced that it would stop using it for mass vaccinations due to concerns about infection.
- 2003: Department of Veterans Affairs recognizes for the first-time ever a veteran acquired Hepatitis C from his military jet injections and awards service-connection for his disability.
- February 13, 2013: The PharmaJet Stratis Needle-Free Injector received WHO PQS Certification.
- August 14, 2014: The U.S. Food and Drug Administration (FDA) approved use the PharmaJet Stratis 0.5ml Needle-free Jet Injector for delivery of one particular flu vaccine (AFLURIA® by bioCSL Inc.) in people 18 through 64 years of age.
References
External links
- Problems in use of jet injectors by diabetics
- Memory Alpha (Star Trek Wiki) page about the hypospray
- Burke F, Brady O (June 1996). "Veterinary and industrial high pressure injection injuries". BMJ. 312 (7044): 1436. doi:10.1136/bmj.312.7044.1436. PMC 2351199 . PMID 8664612.
Source of the article : Wikipedia
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