Channel impulse response inside a magnetic resonance imaging device at 0.8 GHz to 27 GHz

Up to now, wireless transmission in a magnetic resonance imaging (MRI) device is not used extensively for sensor networks or data transmission. Wireless sensors measuring physiological parameters like pulse, ECG, blood pressure or temperature would increase patient safety during a measurement. Beside and rather more interesting is the transmission of MRI sensor data. Patients benefit from higher comfort in the magnet and faster preparation for a measurement procedure. The wireless channels in an MRI device are not well studied at present. In this paper we give a first overview of the available antenna configurations for wireless links and summarize published results. As an MRI device is located in a shielded chamber, the frequency range for a transmission can be chosen freely above the resonance frequencies of the nuclei. To get an insight in the MRI channels we studied in a first approach three exemplary channels at the GSM-900 band, the 5 GHz WLAN band and the 24 GHz ISM band in three scenarios: empty, a real patient, a NaCl-filled tube.