Thecal punctures can be tricky procedures with quite a bit of potential for serious complications. It’s important to know when the needle has reached the cerebrospinal fluid and if it strayed from the target, but this is typically a matter of good training, attention to detail, and having a good hand that can feel as different tissues are penetrated.
Injeq, a Finnish company, developed a new device called IQ-Needle that may take a lot of the guesswork and inconsistency out of performing lumber punctures.