Advanced Five-Plane Lancet Needle Design, Grinding, and Tissue Insertion

The needle with lancet point (NLP), having three planes at the tip to generate a sharp lancet point, is the most common needle tip geometry. This research presents two five-plane lancet needle designs, the five-plane lancet needle with two back bevels (FLN-B) and five-plane lancet needle with two front bevels (FLN-F), to study the effect of two additional bevel planes on the reduction of soft tissue insertion force over that of the NLP. The mathematical models for inclination and rake angles along the cutting edges, and the grinding procedure and setup parameters for FLN-B and FLN-F are developed. Prototype needles are fabricated and the needle insert test was conducted on PVC phantom tissue which mimics the soft tissue. Compared to NLP, FLN-B and FLN-F have higher inclination and rake angles and can reduce the insertion forces by 9.1% and 8.3%, respectively.