NUST Institutions Library Catalogue

Coronary artery diseases remain one of the leading causes of mortality, with the incidence of death rate being 20% in Pakistan. The disease causes deposition of plaque on the lumen of the blood vessels that narrow the coronary arteries (blood) hindering the blood flow to the heart and rest of the tissues. The treatment procedure of the disease involves delivering the expandable device (balloon/stent) to the target region. Guide catheters plays a crucial role for the advancement of these treatment devices (stent/balloon). Guide catheters are hollow tubular structures of 100-110 cm in length, which are required to provide support, and facilitate the delivery of the stent/balloon at the target region. The guide catheter is made to enter the body via the wrist/femoral artery. From here, it traverses all the way to the heart while passing through blood vessels of varying diameter, and a tortuous anatomy of the body. In fact, the pathway of the guide catheter is not a straight, rather a curved path. It is important for the guide catheter to have certain mechanical characteristics to reach the heart without causing any vascular trauma. The performance of the guide catheter heavily relies on its braided shaft, and the outer jacket. Spontaneous movement of the catheter due to its instability, coronary dissections due to a high push force, and arterial spasms resulting from the friction are a few common problems of guide catheters used commercially. The current research is focused on catering these challenges by optimizing the pitch of the braided shaft and jacketing the shaft with a polymer unique to commercial catheters. In order to find the best guide catheter to meet the challenges presented in the literature, three guide catheters of varying pitch were designed, and coated with a polyimide jacket material. The protypes were tested for performance under mechanical, and physically testing and the candidate performing the best was selected. The guide catheter that performed the best in providing the longitudinal stiffness, reducing the friction, and decreasing the push force was chosen, and bench tested.