Architecture and Design of a Low Frequency Mechanical Actuation Device for Pre-Hospitalization Treatment of Myocardial Infarction Patients

One of the major factors in increasing the survival rate of patients suffering from acute coronary ischemia is the speed of intervention. Two major techniques are currently in use: pharmacological and interventional. The former is slow acting and often leads to incomplete reperfusion, while the latter requires specialized personnel and a cathlab. This thesis proposes a novel method for pre-hospitalization treatment of patients with acute coronary ischemia that can be safely applied by a minimally trained individual prior to or during patient transportation to hospital. It consists of applying low frequency mechanical vibration to the left intercostal space of patient’s chest during diastole to induce vibration on the heart and thus on the coronary arteries. Additionally, the method includes application of direct, distal, mechanical, arterial deformation to induce turbulence in the blood flow. Mechanical vibration increases coronary blood flow, acts as a strong vasodilator, and relieves heart spasms likely to be seen in heart attack patients. Direct arterial deformation generates turbulence in the blood, which amplifies mixing of clot busting agents with thrombi. Furthermore, it imposes shear stress on the clot wall to achieve clot displacement and/or disruption. In order to investigate the impact of mechanical actuation on clot lysis and also to examine feasibility of a device for application of mechanical vibration on the chest of myocardial infarction patients, three major studies are presented that also form the three objectives of this work: the first study introduces an electromechanical apparatus to study the effects of mechanical vibration and deformation on disrupting blood clots in-vitro with and without combined use of thrombolytic agents. The second study describes the design and architecture of a prototype device for application of Diastolic Timed Vibration (DTV) on the chest of heart attack patients for increasing the coronary blood flow, and improving the weak relaxation of the ill myocardium. The final experiment presents a preliminary investigation on a human subject to determine whether direct distal arterial deformation could cause turbulence in the blood flow for better mixing of fibrinolytics with clot and induce stress on the clot and the clot wall.