 Leaders for Technical Industries doctoral student Alexandra Sepulveda holds a prototype stent component in the Wardle Lab at MIT An aneurysm can be defined as a permanent and irreversible localized dilatation of an artery, having at least a 50% increase in diameter compared with the common one. It can appear anywhere but it occurs most commonly in the aorta, as well as in arteries located at the base of the brain and in the legs. Two treatments are currently available for the treatment of aneurysms: conventional surgical repair (open surgery) and endovascular aneurysm repair (EVAR). The first involves making a large incision in the abdomen and inserting a prosthetic graft to replace the damaged section of the aorta. EVAR is a minimally invasive procedure in which a stent-graft is guided from the femoral artery to the affected artery segment in order to prevent wall rupture shielding the aneurysm from the blood pressure. This treatment is usually associated with less physiological derangement, lower morbidity and mortality, and more rapid recovery than open surgery but, after the procedure, regular surveillance to detect and prevent complications such as graft migration, stent fracture, endoleaks, enlargement of the aneurysm sac, and AAA rupture is required. Comparing both procedures, EVAR is preferable due to the fact of being less stressful and reducing significantly systemic complications, as well as having lower costs of inpatient stay and less or no need for intensive care facilities during recovery. The durability of open surgery, established with long-term follow-up studies, is excellent, so good that there is little or no requirement for long-term surveillance, in contrast with EVAR whose current results suggest that there is a need for increased surveillance and re-intervention. Considering the longer life expectancies and the rising public expectations for quality of life, the costs associated to the follow-up can jeopardize EVAR’s effectiveness. The current surveillance protocol involves imaging at 1, 6, and 12 months after the procedure, and thereafter, on an annual basis. In order to reduce and even eliminate these exams, new surveillance technologies are being investigated and the most promising technique identified thus far is remote pressure sensing. Remote pressure sensing enables the measurement of both the systolic and diastolic pressures within the residual aneurysm sac at any given point in time. Thus far, the Impressure Sensor and the CardioMems EndoSure Wireless AAA Pressure Sensor (CardioMems, Inc, USA) have been evaluated for abdominal aortic aneurysms (AAA). This project introduces a new pressure sensor for endotension measurement. The focus is on the use of a flexible substrate enabling the conformability of the sensor to the stent-graft and thus the aorta. This aspect brings several advantages, in comparison with available devices, since the sensor can be attached to the stent-graft and delivered in a single procedure (as opposed to the requirement of two catheters for the CardioMems device) and it enables the placement of more than one sensor (a sensor cluster) contributing to a better pos-endovascular aneurysm study (that is currently not available). In addition, new product development methodologies are being studied in order to propose processes that assure products’ success on one hand; and the development of a smart stent-graft on the other hand. Therefore, the new product development strategy tries to identify during the early phases of medical devices’ development which factors influence the diffusion and adoption of innovation; and, will develop a method to select concepts based on their expected cost / benefit. The project is being developed by 4 institutions, University of Minho, Faculty of Engineering of the University of Porto, Instituto Superior Técnico and Massachusetts Institute of Technology, in collaboration with Hospital de S. João. At present, the technology for the fabrication of the sensor is developed and under characterization in terms of mechanical and electrical properties. The pressure monitoring system uses a passive telemetry system, based on an implantable LC resonant network, for the external readout of the pressure sensor signal. The use of passive telemetry in implantable medical devices is common and enables the realization of active implants with no power constraints. The system oscillation frequency was chosen to operate in the frequency band from 12.5 MHz to 20.0 MHz allocated specifically for medical applications. This frequency band presents additional advantages, unlike low frequencies of operation, since the inductors and capacitors require small dimensions and therefore small sensors’ area. The novel smart-stent graft will replace current stent-grafts and will have embedded diagnostic capabilities for leakages and bad placement detection contributing to a reduction of post-surgery surveillance costs and a better quality of life of the patients. Principal investigator: Luis A. Rocha, I3N/IPC - Institute for Polymers and Composites, University of Minho, Portugal, This e-mail address is being protected from spambots. You need JavaScript enabled to view it News coverage about the SenseCardioHealth project in Jornal de Negócios, 17 September 2010 (in Portuguese):  SenseCardioHealth: Jornal de Negócios 17 September 2010
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