There are different setup to acquire the iEEG with the epileptic patients, using 2 different amplfiers: a clinical one and a reserch one
Characteristics of the amplifiers
Clinical amplifiers
Nicolet
This amplifier has been used from xxxx to xxxx in order to record macroelectrodes
- maximum number of channels :
- samplig rate : 400 Hz
- input range :
- bandpass
Micromed: SD LTM 64 BS
This amplifier is used since xxxx in order to record macroelectrodes.
- maximum number of channels : 128 - 2 boxes of 64 inputs each
- samplig rate : 1024 Hz
- input range : +/- 3.2 mV
- bandpass : 0.18 - 220 Hz
Research amplifiers
Neuralynx : Lynx
This amplifier has been used from xxxx to xxxx in order to record only microelectrodes
Neuralynx : ATLAS
This amplifier is used since October 2012 in order to record microelectrodes and macroelectrodes.
- maximum number of channels : 160
- samplig rate : flexible but set to 4kHz for the macroelectrdoes and 32 kHz for the microelectrodes
- input range : flexible but set to +/- 4mV
- bandpass : flexible but set to 0.1 - 1000 Hz for the macroelectrodes and 0.1 - 8000 Hz for the microelectrodes
Electrodes
Macroelectrodes
The macroelectrodes (AdTech®, Wisconsin) consist of 4-12 platinum contact electrodes with a diameter of 1.12 mm and length of 2.41 mm, with nickel-chromium wiring. The distance between the center of 2 contacts is 5 mm.
Microelectrodes
The macro-microelectrodes (AdTech®, Wisconsin) are of the Behnke-Fried type, consisting of 8 platinum contact electrodes with a diameter of 1.28 mm and length of 1.57 mm, embedded on the surface of a polyurethane tube with a hollow lumen. Eight 40 µm platinum-iridium microwires were inserted into the macroelectrode, protruding 3-6 mm into the cerebral tissue beyond the tip of the macroelectrode. The protruding microwires were cut to the desired length during the surgical procedure. The distance between contact 1 and 2 is 3 mm, between 2 and 3, 3 and 4, etc is 7 mm.
Connectors
Acquisition setups (- macroelectrodes / -- microelectrodes)
setup #1: Clinical setup
amplifier:
- Micromed
electrodes:
- macroelectrodes
connectors:
- AdTech
period used
setup #2: Macro and micro electrodes separated
amplifier:
- Micromed
- Neuralynx
electrodes:
- macroelectrodes to Micromed
- microelectrodes to Neuralynx
connectors:
- CHETs for all electrodes
period used:
setup #3: Macro and micro electrodes together, but 2 amplifiers in parallel
amplifier:
- Micromed
- Neuralynx
electrodes:
- macroelectrodes to both systems
- microelectrodes at least to Neuralynx
connectors:
- CHETs for all electrodes
period used:
- start in october 2012
- november 2018
setup #4: Macro and micro electrodes together, only 1 amplifier, using Neuralynx CHETs
amplifier:
- Neuralynx (sent to Micromed PC)
electrodes:
- macroelectrodes to both acquisition PC
- microelectrodes to both acquisition PC
connectors:
- CHETs for all electrodes
period used:
- tests juin 2018
- october 2018
setup #5: Macro and micro electrodes together, only 1 amplifier, using AdTech connectors
amplifier:
- Neuralynx (sent to Micromed PC)
electrodes:
- macroelectrodes to both acquisition PC
- microelectrodes to both acquisition PC
connectors:
- AdTech for macroeletrodes + topHat adapter
- CHETs for microeletrodes
period used:
- tests xxx 2018
- july 2018
Sleep electrodes
Since xx scalp electrodes are added in order to record sleep activity. Some of the electrodes (emg and E1, E2) are removed during the week ends
- O1, Oz, O2
- E1, E2
- C3, M2 or C4, M1 for right and left implantation respectively
For the analysis they should be rereferenced as follow