Available at: http://digitalcommons.calpoly.edu/theses/377
Date of Award
MS in Biomedical Engineering
Biomedical and General Engineering
Heart disease is one of the most prevalent diseases in the world. The survival chances for patients with ventricular fibrillation/ventricular tachycardia reduces significantly as time passes without treatment and even after getting timely treatment recurring episode are common. These patients can benefit from an Implantable Cardioverter Defibrillator (ICD) which can monitor heart rhythm and provide immediate treatment. Due to the ever changing physical conditions and disease progression, the ICD needs to collect diagnostic data as well as support programming by the physician. The ICD uses inductive telemetry and radio-frequency telemetry for the communication with the external devices such as a programmer or a monitor. Inductive telemetry uses less energy than RF telemetry but has a very short range of communication. In addition to inductive telemetry, the St. Jude Medical ICD supports 2.45 GHz band based asynchronized wakeup and 400 MHz MICS band based synchronized wakeup. The 2.45 GHz band based wakeup has limited wakeup range and the 400 MHz MICS based synchronized wakeup has limited availability for connection because it requires synchronization with the base station. The enhanced Medical Implant Communications Service (eMICS) algorithm is a firmware based algorithm which addresses the issues with other two wakeup schemes and provides fast, robust, and seamless wakeup. This thesis describes the design, implementation, and initial testing of eMICS algorithm on the Unity device platform in Technology Project Management (TPM) phase. The eMICS automated test tool developed at St. Jude Medical was used to test the eMICS algorithm under a controlled lab environment, typical home environment, typical hospital/clinic environment, and in the field. The project was successfully completed and transferred to Product Project Management (PPM) phase. However, the suggested duration of 60-90 seconds for sniff interval which will cause the least effect on the battery life was found unacceptable, and there is also a strong need for energy efficient hardware which draws minimal amount of current during each sniff. Therefore, St. Jude Medical is collaborating with the hardware vender to implement eMICS algorithm in the next version of hardware.