| Narrowing of the blood vessel, stenosis, can occur throughout the human blood vessel system. When it occurs inside the vessel feeding limbs, the blood pressure drops causing chronicle pain. Modern three dimensional medical imaging technologies can give the diagnosis of stenosis or can help for preoperative procedure. These costly equipments produce high levels of radiation on the patient and often require the injection of a contrast agent to enhance the vascular tree viewing. Ultrasound imaging is under research as an alternative to 3D imaging. It is a non-iodizing low cost technology. Robots are also currently being developed to perform the ultrasound scan of a patient using a probe. The robot can help the radiologist and eventually allow automation of the examination with its constant position monitoring. This thesis presents a new robot design for 3D examination of lower limb arteries. This robot was designed with great concern for the safety of the patient and the surrounding medical staff. Given in the absence of safety regulations for medical robots, appropriate safety measures were developed following a thorough literature review. The proposed parallel robot allows internal forces to be distributed among all motors. The robot dimensions were calculated to allow the scanning examination of the longest arterial: the lower limb arteries. All other arterial examinations are less demanding in terms of workspace size. Static balancing mechanical components were added to predict and secure the robot's movements in case of sudden power outage and to reduce the gravity effect on motors. |
