A Room Temperature Atomic Magnetrode System for Telemetry of Epileptic Seizures

Overview

This study is being done to help scientists learn about the use of a device called an atomic magnetometer. The device uses sensors called optically-pumped magnetometers (OPM) which function at room temperature. This research will compare the non-invasive brain imaging application of the OPM sensors to the present SQUID-based cryogenic sensor technique used in conventional Magnetoencephalography (MEG). This study is being conducted in conjunction with the University of Colorado Boulder's Mechanical Engineering Department.

Investigators at UC Boulder have an active program to develop "chip-scale" optically-pumped magnetometer (OPM) sensors, which combine high sensitivity with small size, low cost and low power operation. These sensors are an attractive alternative to superconducting quantum interference device (SQUID) magnetometers for the reasons outlined below, but remain largely unverified for use in biomagnetic applications. While considerable testing can be carried out without the use of humans, human testing is considered essential to encourage acceptance of this technology by the biomagnetic research community and more broadly by the medical community. The goal of this research is to assess and validate how well the new types of sensors perform for non-invasive brain imaging and to optimize and improve their performance for imaging. The goal is to show that these sensors are not just more economical and easier to use, but also improve signal quality. In this project specifically, OPMs can prove usefulness for telemetry, which means that long-term measurements over several days are possible, in principle. This is important, since these non-invasive imaging with these OPM sensors might be able to use replace the invasive imaging with implanted electrodes (electrocoticography (EcoG) for pre-surgical mapping of epileptic seizures. The project proposes to compare the use of OPM and SQUID sensors during recording spontaneous and evoked brain activity in healthy human volunteers as well as in patients with intractable epilepsy. Two objectives: (1) to show that the patient can move with a confined area during measurements (this is currently not possible with rigid MEG systems) and (2) to show that images can be generated with a spatial resolution equivalent to that of internal electrodes.