Jet Injectors = Jet Infectors
Edited: December 17, 2017
Samir Mitragotri, while a chemical engineer at the University of California, visually captured the discharge of jet injectors using high-speed microcinematography (Mitragotri, 2006). The photos in the following link demonstrate a close-up look at the jet injection process. Most importantly, notice in the images when the high velocity stream penetrates the skin there is extensive splash back.
“The black region at the top of each image shows the outline of a jet injector with the protrusion in the centre showing the position of the nozzle,” said Mitragotri. “The black region at the bottom shows the outline of human skin.” The white space between the two black regions is a gap, approximately a few millimeters wide between the jet injector and human skin.
In the photo where the time equals 0, the jet injector has been activated.
By the time of 40 μs (i.e., Microsecond) the jet stream appears from the orifice and by 160 μs the jet stream makes initial contact with the skin. For reference purposes one microsecond equates to one millionth of a second.
From 280 μs to 1 ms (i.e., Millisecond) the penetration of the jet stream caused excessive splash back. Mitragotri stated, “The typical volume of the liquid splashed in the image at 400 μs is around 100 nl [i.e., Nanoliter] (Mitragotri, 2006).
The deposition of the liquid medicament between 2 to 5 milliseconds (ms) causes a wheal, or rather a bulge under the skin. This wheal will diminish over time as the ejected fluid absorbs into surrounding tissues.
Mitragotri’s photographic evidence leaves no dispute, during the natural injection process that was intended by the manufacturer, the nozzle frequently became contaminated. Thus, the jet injector became unsterile and therefore unsafe. Moreover, this evidence corroborates the testimonies of veterans who visually saw blood on the nozzle of the jet injector during their military mass vaccination campaigns.
- (Mitragotri, 2006) Mitragotri S. Current status and future prospects of needle-free liquid jet injectors. Nature Reviews Drug Discovery 5:543–548, 2006. Accessible at: http://www.nature.com/articles/nrd2076.
This article was originally published on January 17, 2016 and can be viewed here.