Finite element analysis of needle insertion angle in insulin therapy

Millions in the world suffering diabetes mellitus depends on insulin therapy to control their blood glucose level daily. However, the painful daily injections they need to take could lead to other complications if it is not done correctly. To date, it is suggested by many researchers and medical doctors that the needles should be inserted at any angles of 90^o or 45^o. Nevertheless, this recommendation has not been supported by clinical or biomechanical evaluation. Hence, this study evaluates the needle insertion for insulin therapy to find the favourable angles in order to reduce injury and pain onto the skin. Finite element analysis was done by simulating the injection of three-dimensional (3D) needle model into a 3D skin model. The insertions were simulated at two different angles, which are 45^oand 90^o with two different lengths of needles; 4 mm and 6 mm. This study concluded the favourable angle for 4 mm needle to be 90^o while 6 mm needle was best to be inserted at 45^o as these angles exerted the least maximum stress and strain onto the skin.