Medical Venipuncture/cannulation physics

[VacuumAce]

I am not sure if any of guys are familiar with venipuncture/cannulation as it belongs to the medical field lol. The thing is I read a lot of tips/rules on them like how to find the veins etc. ,but ironically there are almost no tips on how to poke the vein other than saying that you need to poke at a 10 degree to 30 degree or 45 degree.(Veins roll a lot even if you anchor them before you poke) Is a higher angle easier to poke a vein or a lower angle,as in does it have more force applied to it or something?

 

[pat8126]

"Starting with a steeper angle reduces the amount of dermal tissue punctured by the needle and reduces the axial insertion force at the needle tip. And ending with a shallow angle reduces the likelihood that the needle tip pierces through the other side of the vein."

Real-time Needle Steering in Response to Rolling Vein Deformation by a 9-DOF Image-Guided Autonomous Venipuncture Robot
Alvin I. Chen, Max L. Balter, Timothy J. Maguire, and Martin L. Yarmush
Rep U S. 2015 Sep-Oct; 2015: 2633–2638. doi: 10.1109/IROS.2015.7353736

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4714798