Implantable multi-sensor system for hemodynamic controlling

Abstract

A miniaturized implantable multi-sensor system for cardiovascular monitoring of physiological parameters is presented. High accuracy pressure measurements within the vessel can be performed by a capacitive pressure sensor. Additional information about the patient, e. g., sudden movement, inclination or increased temperature can be obtained by additional sensor components such as an acceleration sensor and a temperature sensor unit. This information facilitates compensation of interferences for more accurate pressure measurements. A multi-functional ASIC enables, amongst others, sensor signal processing, power management and telemetric communication with extracorporeal electronics. Sensor chips, the multi-functional ASIC and passive components are assembled on a LTCC circuit board in which an antenna coil is integrated for telemetric energy and data transmission at a frequency of 13.56 MHz. In order to support further miniaturization, the implant shall be encapsulated with a stack of very thin and hermetic ceramics applied by ALD instead of using bulky metal housings. Further encapsulation with polymers, which can be functionalised with appropriate biomolecules, is necessary for a proper shape, a biocompatible interface to the surrounding tissue and, thereby, reduction of thrombogenicity.