Full-Duplex intercom system for MRI scanners

The system , through the use of a active EMC filter with his analog gain control, allows a comfortable communication between operator and patient. The operator has a choice of microphones:
handsfree communication through the built-in microphone, an optional gooseneck microphone installed on the operator’s unit for extreme noise conditions.
In normal working conditions no manual operation is required once the system is switched on.
The volume in both directions is pre-set per position by screwdriver adjustments accessible from the rear of the cabinet.
The three buttons in addition to the “ON/OFF” button are included to take care of special conditions which may occur during use: “Microphone selector” button with lamp for switching to an optional microphone fitted to the operator’s unit. This enables hands-free communication even in periods of high noise levels on the operator’s side.

The system is designed for hands-free, voice-controlled full-duplex conversation between counter personnel (operator) and MRI patients.

Features

  • Full-duplex speech (talk and listen simultaneously)

  • Active EMC filter with gain control

  • Excellent speech quality

  • Listening with microphone switched off at the operator station

  • Volume adjustable for operator and patient

  • Fast and easy to install

TECHNICAL SPECIFICATIONS

OPERATOR’S UNIT
  • Dimensions (WxHxD) 93 x 65 x 224 mm
  • Weight (net) 350 g
  • Environmental condition cat. T1, CE requirements
  • Supply voltage 12.0 V d.c. ±0.5 V
  • Current consumption typ. 100 ma
  • min. 42 ma, max. 180 ma
  • Output power, patient side max. 500 mW
  • Output power, operator’s unit max. 350 mW
EMC ACTIVE FILTER KIT
  • 1 shielded case aluminium
  • Dimensions (WxHxD), each 65 x 60 x 150 mm
  • Weight, each 300 g
  • Supply voltage 12.0 V d.c. ±0.5 V
  • Current consumption max 100 mA
  • Analog gain control
EXTERNAL MICROPHONE
  • Type AKG C 400 BL Hypercardioid, electret
  • Frequency range 150 Hz – 12 kHz @ -6dB
  • Dimensions (L x H x D) 43 x 24 x 12 mm
  • Sensitivity at 1000 Hz 13.5 mV/Pa, -37 dBV
  • Shielded cable 5 m
LOUDSPEAKER KIT
  • 1 cabinet silver brown ABS plastic
  • Dimensions (WxHxD), each 105 x 106 x 62 mm
  • Weight, each 180 g
  • Loudspeaker element Philips AD 3071/Y50
  • Power capacity 2 W max.
  • Impedance 50 ohms
  • Cable length, total 10 m
OPTIONAL EQUIPMENT
  • Gooseneck microphone 220 mm,
  • Electret, 7.2 mV, 1 Kohm