Publication Date

2019

Document Type

Thesis

Committee Members

Tarun Goswami (Advisor), Caroline Cao (Committee Member), Ulas Sunar (Committee Member), Abdul Wase (Committee Member)

Degree Name

Master of Science in Biomedical Engineering (MSBME)

Abstract

Approximately, 92.1 million patients in the US suffer from cardiovascular diseases with an estimated healthcare cost of over $300 billion; out of which at least one million patients have Cardiac Implantable Electronics Devices (CIED). CIED represented by pacemakers, Implantable Cardioversion Defibrillator (ICD), and Cardiac Resynchronization Therapy (CRT) are exposed to in-vivo damage. These damages are complex and composed on multiple levels and present challenges while assessing their combined extent. Since 2004, more than one hundred recalls were reported for cardiac devices. ICD devices had the majority with 40.8% recalls, pacemaker recall percentage was 14.5%, CRT recall percentage was12.7%, leads recalls were 9.7%, and others (stents and LVAD) with 22.3% recalls. The objective of this research is to investigate the damage of the cardiac devices and the changes in the residual properties after in-vivo implantation, such knowledge will lend insight into the common damage patterns, controlling the probability of failure in the design of future devices, and improve reliability. In-vivo damage assessment was performed on 65 retrieved cardiac devices and 136 leads from different manufacturers (Medtronic, St. Jude Medical-Abbott and Boston Scientific). The examined damage features were surface deformation, burnishing, pitting, scratching, discoloration, delamination, insulation defects, coil damage, and abrasion. The results showed that the main damage mode observed was scratching, and the anterior side of the Pulse Generator (PG) was more exposed to damage than the posterior side. Additionally, the middle part of the lead was more exposed to damage than the proximal part. Tensile test was also performed on new and retrieved Medtronic 5076 CapSureFix Novus MRI SureScan leads. Load to failure showed a significant decrease after 18 months of in-vivo exposure (P-value =0.0008). Percentage elongation showed a significant decrease after 94 months of in-vivo exposure (P-value<0.0001). Ultimate tensile strength showed significant decrease after 73 months of in-vivo exposure (P-value=0.0339) and percentage elongation at 5 N force showed significant decrease after 66 months of in-vivo exposure (P-value =0.0037). On the other hand, modulus of elasticity has direct proportion with the number of in-vivo months and showed significant increase (P-value=0.0051) after 73 months of in-vivo environment. In conclusion, it can be inferred that the as received pulse generator had mainly scratches that were shallow, narrow and could not have affected the functionality of the devices. The as received leads had visible insulation defects, stretches, and coil damages that could have caused different types of failures and could have affected the functionality of the devices.

Page Count

150

Department or Program

Department of Biomedical, Industrial & Human Factors Engineering

Year Degree Awarded

2019

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