[HN Gopher] Jet Automatic Hypodermic Injection Apparatus - Vacci...
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       Jet Automatic Hypodermic Injection Apparatus - Vaccine Gun (2021)
        
       Author : areoform
       Score  : 25 points
       Date   : 2022-12-11 04:37 UTC (18 hours ago)
        
 (HTM) web link (americanhistory.si.edu)
 (TXT) w3m dump (americanhistory.si.edu)
        
       | areoform wrote:
       | I learned today that these are real-life hyposprays. In fact, the
       | Star Trek hyposprays are named after the brand name for one of
       | these. Here's a photo of what these look like in action,
       | 
       | https://pbs.twimg.com/media/Fjooo0jXEAEri7D?format=jpg&name=...
       | 
       | They work with pressure to deliver a dose of the vaccine
       | subcutaneously without needles. (I had always thought that they
       | were some kind of needle-based injector instead)
       | 
       | I just think it's so cool that we already have hyposprays and
       | it's a thing that we can improve! And deploy everywhere,
       | including dense jungles. These worked on _literal pedal power_.
       | _And_ were painless.                   > Hingson's device used a
       | piston to propel the vaccine at a rapid speed into and under the
       | skin--the vaccine moved so quickly and under such pressure that
       | no needles were needed. Public health practitioners gleefully
       | noted that this method of vaccination was so painless that it
       | could be used on a sleeping baby. But best of all, the jet
       | injector could hold 500 or more doses of vaccine, meaning that
       | hundreds of doses could be delivered within an hour.
       | 
       | Alas, they were phased out due to backwash and contamination from
       | the injection process. But that's a fixable problem. I think.
        
         | tgsovlerkhgsel wrote:
         | > phased out due to backwash and contamination from the
         | injection process. But that's a fixable problem. I think.
         | 
         | I'm kinda glad that they don't keep trying to fix it in
         | production when a good enough alternative exists.
         | 
         | (Backwash = spreading disease from one patient to the next, and
         | nasty stuff too like Hepatitis)
        
         | klyrs wrote:
         | > Alas, they were phased out due to backwash and contamination
         | from the injection process.
         | 
         | That's how the army gave my aunt Hep C. Numerous attempts have
         | been made to solve this "backwash" issue, but fluid dynamics is
         | a harsh mistress. When you shoot a droplet at a fluid
         | interface, the interface shoots back.
        
         | ratsnake wrote:
         | I only received one injection with this device, but I can tell
         | you it wasn't painless. In fact, it was by far the most painful
         | injection I've ever had.
        
           | areoform wrote:
           | I'm sorry that you experienced that! Would you happen to know
           | what kind of injection you had? Was it subcutaneous,
           | intradermal, or intramuscular? And what kind of vaccine was
           | it?
           | 
           | I found a study addressing the pain and the authors theorized
           | that the depth of the injection determined the pain
           | experienced by the patients,
           | https://www.pnas.org/doi/full/10.1073/pnas.0700182104
           | > Motivated by the limitations of injections, needle-free
           | liquid jet injectors were invented more than 50 years ago (4)
           | and have been used for delivering several vaccines and
           | protein drugs. More recently, a number of other technologies
           | have also been proposed to deliver proteins across the skin
           | without using needles (5-13). These technologies are at
           | varying degrees of development. As of today, however, liquid
           | jet injectors comprise the only needle-free tool in the hands
           | of clinicians for delivery of proteins and other
           | macromolecules. Commercially available liquid jet injectors
           | use compressed gas or a spring to create high-pressure jets
           | of drug solutions that deliver drugs in the s.c. or i.m.
           | region (14, 15). Despite their long history, needle-free
           | liquid jet injectors have been met with disappointing
           | acceptance as a result of frequent bruising and pain (4),
           | which immediately offset their advantages against needles. We
           | hypothesized that pain and bruising originate from deep
           | penetration of jets into skin leading to their interactions
           | with nerves and blood capillaries. This issue could
           | potentially be addressed by minimizing the penetration depth
           | of jets into the skin; however, attempts to reduce the
           | penetration depth have led to a concurrent loss of delivery
           | efficiency (16). Decoupling penetration depth and delivery
           | efficiency has been difficult as a result of the very design
           | of conventional jet injectors. We overcame this issue by
           | adopting a new strategy of jet injection, pulsed microjets.
           | We propose the use of high-velocity microjets (v >100 m/s) to
           | ensure skin penetration but small jet diameters (50-100 mm)
           | and extremely small volumes (a few nanoliters) to limit the
           | penetration depth. We describe a microjet device that meets
           | these criteria and demonstrate its capabilities by using
           | insulin as a model drug.
        
           | cptskippy wrote:
           | In my limited experience, high pressure pneumatic wounds are
           | accute blunt force trauma and the pain is intense and long
           | lasting.
           | 
           | It doesn't surprise me that this would hurt a lot.
        
           | [deleted]
        
       | o_1 wrote:
       | does this produce the polio vaccine scar we most commonly see on
       | people born 1950-70
        
         | digitalblade wrote:
         | No... https://www.healthline.com/health/smallpox-vaccine-scar
        
       | zoom6628 wrote:
       | Looks like gear that vets and farmers still use.
        
       | jokowueu wrote:
       | They keep saying it's painless but I've heard more than once
       | that's it's very painful.
        
       | GuB-42 wrote:
       | Side note, high pressure injection was and still is a common
       | workplace accident[1].
       | 
       | It happens when you work with highly pressurized fluids, like
       | with a grease gun, and there is a leak. The high pressure jet can
       | penetrate your body without too much visible damage, but you just
       | injected yourself with nasty chemicals, and the consequence can
       | be serious, or even fatal.
       | 
       | The jet injector idea was that if high pressure jets can inject
       | people with poison, why not use the same principle to inject
       | medicine.
       | 
       | [1] https://en.wikipedia.org/wiki/High_pressure_injection_injury
        
         | daniel_reetz wrote:
         | Also a hazard when operating a waterjet cutter. Mine came with
         | cards that advise the doc to treat the wound like a gunshot
         | wound.
        
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       (page generated 2022-12-11 23:01 UTC)