ADVANCEMENTS IN IMPLANTABLE CARDIOVERTER DEFIBRILLATOR (ICD) DEVICE DESIGN TO INCREASE PATIENT COMFORT

摘要

ICDs have the potential to cause physical discomfort for the patient and are typically implanted on top of the pectoral muscle and under subcutaneous tissue. High skin pressures and skin strains in the implant site, or pocket, have been theorized to be an indicator of discomfort, or in extreme cases, skin erosion. A reduction in skin pressures can be assumed to be consistent with an increase in overall patient comfort for subcutaneous implants, ref. Pocket size is governed by each physician's implant technique and overall device shape. A major change in the approach to device design has been the introduction of a more physiologic shape when compared to historical designs. To achieve a more physiologic shape, designers contoured the shield (blue, Fig. 1) and the header (yellow, Fig. 1) of device A to avoid the small radius corners often seen on square, flat devices. Removing corners allows for a smoother transition of skin around the device and reduces potential high strain and pressure areas between the device and the skin. A contoured header is especially important as the header of most devices contains grommets (seals used to cover screws which are tightened, securing the leads) which are often backfilled with medical adhesive (MA), leaving a protrusion from the surface of the header. This novel work assessed the impact of device design change on patient comfort through finite element contact modeling.