Extensive sensitivity analysis of Implantable Cardioverter Defibrillators by an Automatic Sensing Test procedure

An Automatic Sensing Test methodology, in the following indicated as AST, is presented in this paper. The AST permits an extensive sensitivity analysis of implantable cardiac medical devices, among which Implantable Cardioverter Defibrillator (ICD). The AST is designed to evaluate the thresholds of the ICD sensing, considering different heart rates. In this way, it is possible to take into account different patient’s states of health. Consequently, it is possible to obtain a comprehensive assessment of ICD sensing performance. The AST is fielded through an optimized automatic measurement system implemented by means of an accurate general-purpose hardware platform. The procedure is based on dedicated virtual instruments. The developed environment is LabVIEW, by the National Instruments. The characterization process is based on an extensive experimental validation and field testing, which have been carried out by employing different ICD sensitivity settings and in two different scenarios: a 3- meter-high semi anechoic Radio Frequency Chamber, which is suited for electromagnetic pre-compliance test due to proper shielding against external electromagnetic noise, and an unshielded environment, which is more common for ICD operation. Detailed results are shown and discussed. They prove the validity of the proposed AST in both environments, in terms of a more extensive ICD characterization than that achievable by the Sensitivity Test described in the international standards, which is the starting point of the proposed procedure.