Evaluation of Radiopacity and Biocompatibility of Sensor Package for Smart Catheter Application

Smart catheters integrated with multiple sensors measure and provide surgeons with physiological data such as temperature, heart rate, pH value, blood flow or pressure. This feedback information enabled surgeons to better monitor and evaluate a patient's condition during the procedure. Thus, surgeons will be able to make accurate medical intervention and lead to a better health outcome for the patient. However, there is a growing trend to employ smaller catheters for certain procedures. Challenges faced by smart catheters include limited space for sensors integration which promotes the initiative to minimize sensor packaging. This led to secondary challenge of radiopaque visibility and biocompatibility for such sensor package. In this work, radiopaque visibility studies have been conducted and a minimum tungsten thickness of 100um is required for a sample size of 1.8mm (L) x 0.7mm (W). Additional radiopaque ink can be used as an alternative for die attach adhesive. The sensor package includes a polyimide-nitinol based flexible circuitry substrate with silicon-based sensor chip, radiopaque material (tungsten) and epoxy encapsulant has been verified to be biocompatible and suitable for catheter-based application.