Predicting charge-times of implantable cardioverter defibrillators

A novel method of validation of the mathematical model for batteries that power Medtronic's Implantable Cardioverter Defibrillators (ICDs) is presented. In a conventional approach used in the past, the model has been validated against data collected in controlled laboratory conditions. To supplement this approach, we now validate the model against ICD performance data reported from devices used in the field for periods ranging from about five to seven years. The key model output is ICD "charge time" - the time required to charge a high voltage capacitor in preparation to deliver shock to the heart. This validation is carried out for five of Medtronic's ICD designs and very close agreement is obtained between model predictions and field data.