Calculating RF-Induced Voltages for Implanted Medical Devices in MRI Using Computational Human Models.

Despite its import as a diagnostic tool, patients with active implantable medical devices (AIMDs) are generally denied access to magnetic resonance imaging (MRI). The complexity of MRI environments stems from a multiplicity of fields and numerous scan parameters. In order to perform a risk assessment for RF-induced malfunction, manufacturers perform electromagnetic simulations using computational human models (CHMs) to calculate RF induced energy at the AIMD ports.

Virtual Humans for Implantable Device Safety Assessment in MRI: Mitigating Magnetic Resonance Imaging Hazards for Implanted Medical Devices.

Magnetic resonance imaging (MRI) is the preferred modality for soft tissue imaging because of its nonionizing radiation and lack of contrast agent. Due to interactions between the MR system and active implantable medical devices (AIMDs), patients with implants such as pacemakers are generally denied access to MRI, which presents a detriment to that population. It has been estimated that 50-75% of patients with a cardiac device were denied access to MRI scanning and, moreover, that 17% of pacemaker patients need an MRI within 12 months of implantation [1].

MR conditional safety assessment of implanted medical devices: advantages of computational human phantoms.

Until recently, patients with active implantable medical devices (AIMDs) have been contraindicated for magnetic resonance imaging (MRI). Current efforts to demonstrate safety of these devices separate the interaction of the device and MRI into several hazards. For several of these hazards, computational human phantoms (CHPs) are used to provide conservative conditions for a risk-based analysis.

SAW-LC coupled resonator wideband VCO for medical telemetry.

Wireless links with implantable devices can help in real-time monitoring of symptoms, irregularities, implanted device efficacy and their reconfiguration. We present the design of a low-power wideband voltage controlled oscillator (VCO) to facilitate implantable wireless telemetry. A coupled SAW-LC resonator design combines high Q and spectral purity of a SAW element and tunability of an LC-tank.

Probability of Interference between LP-LDC and LBT MICS implants in a medical care facility.

The latest generation of medical implants incorporate RF telemetry to facilitate communication of patient data to the patient's physician. Regulatory agencies have enabled medical implant telemetry by allocating RF spectrum in the 402-405 MHz band. The first generation of regulations mandated the use of a Listen-Before-Talk (LBT) protocol.