Mind Mirror III

 
The Real-time Brain Wave Spectrum Analyzer.

Key Characteristics

• Small portable EEG
• Easy connection to supplied EEG electrode harness
• Displays and stores on a PC based computer through an electrically isolated fibre optic modem.

The Mind Mirror series of instruments has pioneered the discovery of brain states and their relation to subjective states of mind.

The Mind Mirror III is a standalone EEG, designed to show visually the presence of Alpha, Beta, Theta and Delta. This is displayed in a unique format as two arrays on a Liquid Crystal Display or a PC CGA screen. Each array shows independently
and simultaneously the electrical activity in the left and right hemispheres of the brain in the area of the electrodes. Every subtle change is clearly shown.

The Mind Mirror III hasthe following features:-

• 15 Bargraph outputs per hemisphere
• Session Recording - At the touch of a button the Mind Mirror III
  starts recording the display. Another button allows the session to
  be reviewed.
• Computer Communications - A recorded session can be sent to a
  computer using the supplied cable. Optionally the display can be
  sent as it is happening to a computer using a fiber optic cable.
• EMG Activity - A separate bargraph is devoted to monitoring
  muscle tension on each side of the head

Mind Mirror III Specification

The Mind Mirror III is a twin channel electroencephalograph (EEG) which performs instant frequency analysis and displays the results on horizontal barographs on an LCD. Expanding barographs moving right show the magnitude of the signal in the right hemisphere, and barographs moving left show the magnitude of the signal in the left hemisphere. Each bargraph represents the output of one filter.

The barographs are centered on the following frequencies: 0.75Hz, 1.5Hz, 3Hz, 4.5Hz, 6Hz, 7.5Hz, 9Hz, 10.5Hz, 12.5Hz, 15Hz, 19Hz, 24Hz, 30Hz and 38Hz. The bandwidth of each bargraph is adjusted so that the 3db loss points coincide with the equivalent points of the adjacent filter. A separate EMG bargraph displays the magnitude of frequencies in a 100 to 200Hz window. EEG filter frequencies can be supplied to custom specifications on request.

Maximum input sensitivity is 3 microvolts. The wideband noise is less than 1 microvolt. The sensitivity may be switched between 3, 5, 10, 30, 50 or 100 microvolts rms. The CMR response is better than 60db. A built in test oscillator checks the performance of the Mind Mirror III and when connected to a subject, is used to check the quality of the head contact. The test signal level is approximately 100 microvolts and cannot harm the subject.

The last 30 minutes of use is automatically recorded and can be sent after the session to an MS-DOS® computer. This uses a supplied cable terminating in an RS232 9 pin D type connector. For safety reasons the electrodes and computer cable use the same socket and can't be plugged in together. Real-time communications uses a fiber optic lead which plugs into the back of the unit and terminates in an RS232 9 pin D type connector.

The Mind Mirror III uses a microprocessor to process the signal and then display them on the LCD.

The instrument is battery operated so that the subject is in no danger of electrocution.

The Mind Mirror III is housed in an attractive hard white plastic unit with a sloping front panel for ease of use, measuring254mm wide x 127mm deep x 107mm high.

A carrying case containing the Mind Mirror III, head band, harness, electrodes, one tube of jelly and an off-line computer cable is supplied with the unit. The carry case measures 47cm wide x 34cm deep x 18cm high.