In this NIH SBIR Phase II, Actuated Medical, Inc. will finalize and clinically test the Active Fine Gauge Spinal Needle with CSF Sensing to Minimize PDPH and Dura Damage. Phase I achieved all Specific Aims and demonstrated that the Smooth Insertion Spinal (SIS) System provided greater control for the clinician by reducing the buckling of 27G traumatic needles during insertion. Tip penetration into the subarachnoid space with cerebrospinal fluid (CSF) flow was electronically detectable 4 times faster compared to visual flashback. Clinician focus groups (N = 20) agreed that the SIS technology would be advantageous in placing 27G needles. Phase II Aims and goals are based on conversations with regulatory experts (CE Mark and FDA) and clinicians, and are structured to obtain regulatory clearance/approval. Spinal anesthesia is a form of regional anesthesia involving injection of drugs directly into the subarachnoid space. Spinal anesthesia provides many benefits over general anesthesia, including decreased post- anesthesia nausea and vomiting, and more effective post-op pain control. The most common complication is a Post Dural Puncture Headache (PDPH), caused by leakage of CSF through the residual hole in the dura left by the deliberate needle puncture. PDPH can last from hours to weeks and can require extended hospitalization, bed rest, medication, and/or possible treatment with a blood patch. In 2008, in the U.S., 30,324 PDPH cases resulted in extended hospital visits and 16,912 spinal blood patches. PDPH is one of the Top Three reasons for litigation against obstetric anesthesiologists. PDPH is reduced up to 65% by using fine gauge (e 25G) and more atraumatic (non-cutting) tipped needles. Unfortunately, finer atraumatic needles can buckle, deflect, or even break during the procedure. Repeated insertions and redirections, which increase PDPH risk, can result from a) the difficulty in feeling the 'pop' into the thin dural sheah, and b) the time needed to confirm CSF contact. A device is needed that can improve spinal anesthesia outcomes by allowing fine gauge (27G) atraumatic needles to be smoothly and accurately inserted with earlier confirmation of entry into subarachnoid space. SIS solves these clinical shortfalls. SIS will detect CSF flow in needles prior to CSF flashback in 91/96 (95%) insertions in porcine model, rate of 95% confirmed with a 'one-proportion' hypothesis test with =0.05. Additionally, SIS will be safe and effective for 27G atraumatic spinal needle insertions in 10 of 10 human patients. Aims: 1) Final Optimization and Verification of Sensing Electronics for CSF and Bone Contact and Pre-validate SIS Design (AMI, Mo. 1-12), 2) Demonstrate Safety and Effectiveness in Live Animal Model (AMI/HMC, Mo. 13-16), 3) Verification and Validation with Production of SIS Beta Prototype (AMI Mo. 14-18), 4) Pilot Human Clinical Evaluation (AMI/HMC, Mo. 18-24).