Needle biopsy is a common medical procedure where a needle is guided into the body and used to cut and remove tissue for evaluation. The geometry of needle tip and speed of insertion are important to the efficiency of tissue cutting. This study investigates the mathematical model on the needle tip cutting edge, which is divided into several elementary cutting tools (ECT). The cutting edge is modeled as ECTs with constant inclination angle (λ). A blade oblique cutting machine was developed to test the cutting of bovine liver and phantom gel work-materials by inserting a thin sharp blade at different inclination angles. Experimentations performed reveals phenomena associated with cutting of soft tissue and tissue-like materials. Increased speeds and decreased inclination angles lead to higher cutting forces. This study also reveals that it is challenging to determine the exact location for the inception of blade cutting of soft tissue due to the large workpiece deformation.