MRI interactions of a fully implantable pressure monitoring device.

Purpose: To investigate the potential patient risk and interactions between a prototype implantable pressure monitoring device and a 3T clinical magnetic resonance imaging (MRI) machine to guide device design towards MR Conditional safety approval.

Materials And Methods: The pressure monitor device contained a catheter-mounted piezo-resistive pressure sensor, rechargeable battery, wireless communication system, and inductive pickup coil. Standard testing methods were used to guide experiments to investigate static field induced force and torque, radiofrequency (RF)-induced heating, image artifacts, and the MR's effect on device function.

Chronic measurement of left ventricular pressure in freely moving rats.

Measurements of left ventricular pressure (LVP) in conscious freely moving animals are uncommon, yet could offer considerable opportunity for understanding cardiovascular disease progression and treatment. The aim of this study was to develop surgical methods and validate the measurements of a new high-fidelity, solid-state pressure-sensor telemetry device for chronically measuring LVP and dP/dt in rats. The pressure-sensor catheter tip (2-Fr) was inserted into the left ventricular chamber through the apex of the heart, and the telemeter body was implanted in the abdomen.

Implantable ICP monitor for improved hydrocephalus management.

Background: Hydrocephalus patients are commonly treated by insertion of ventriculoperitoneal shunts, but these have high complication rates. Monitoring of shunt and patient condition can be achieved through measuring intracranial pressure (ICP). Significant zero drift has limited previous developments towards a long-term implantable ICP monitor.