Implantable shunt system and associated pressure sensors

Abstract

A hermetically sealed biocompatible pressure sensor module configured for implant at a desired site at which a pressure is to be measured. Anodic bonding of the pressure module package components which have similar thermal coefficients of expansion provides low stress bonding and maintains long term reliability, dependability and accuracy. The pressure sensor module includes a pressure sensitive membrane which is in direct contact with the environment at which a pressure is to be measured. The pressure sensor module forms a part of a pressure measuring system which uses a telemetry link between the pressure sensor module and an external controller for data transmission and transfer. Operating power for the pressure sensor module is provided by the external controller and an internal rechargeable energy storage component. Accordingly, the pressure measuring system provides a dual stage power and data transfer capability for use with an implantable system. An exemplary use of the pressure sensor module is in a three pressure sensor system including a flow control valve in a shunt to treat hydrocephalus. The use of integrated circuit chips and an internal coil with an optional ferrite core in the pressure sensor module provides for low power consumption and reliable signal processing. An embodiment of the invention includes a pressure sensor and associated electromagnetic coils embedded in the tip portion of the shunt for measuring the pressure of fluid externally of the shunt at the tip portion.