4 ms·

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.

deleted 4y ago
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cptskippy 4y ago
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.
areoform 4y ago
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 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 μm) 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.

deleted 4y ago

[deleted]

cptskippy 4y ago

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.

areoform 4y ago

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 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 μm) 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.