 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
 |
|
| Is the sample-rate adjustable on a BioSemi system ? |
Yes, the new ActiveTwo system has 4, user selectable sample rate options: 2, 4, 8 or 16 kHz per channel. |
| Analog bandwidth (-3dB) is always 1/5th of the sample rate. The system has a 10-way rotary switch on the front panel to select 2 kHz (400 Hz bandwidth), 4 kHz (800 Hz), 8 kHz (1600 Hz) or 16 kHz sample rate (3200 Hz bandwidth). The sample-rate/NR-of-channels setting is selected in the front-end, the front-end determines which channels at which sample rate are sent to the PC. ActiView can always downsample the data in order to reduce the file size. |
| You can find out what model AD-box you have by running ActiView and then select the 'About' Tab-page. There will be shown either MK1 or MK2. |
AD-box model MK2
AD-box switch |
Sample-rate |
Pin channels + EX channels + Sensor channels |
0 |
2048 (2 kHz) |
Daisy-chain mode: In speedmode 0 to 3, the AD-boxes work as up to 4 optical fiber 'daisy chained' boxes, each with a maximum of 128+8 channels+sensors @ 2 kHz, speedmode switch = box number. (0=Box1, 1=Box2, 2=Box3, 3=Box4). Daisy chain possibilities are not standard included in the base system price. |
1 |
4096 (4 kHz) |
|
2 |
8192 (8 kHz) |
|
3 |
16384 (16 kHz) |
|
4 |
2048 (2 kHz) |
256+8+7 |
5 |
4096 (4 kHz) |
128+8+7 |
6 |
8192 (8 kHz) |
64+8+7 |
7 |
16384 (16 kHz) |
32+8+7 |
8 (AIB-mode) |
2048 (2 kHz) |
256+8+7+32AIB |
9 (ABR-mode) |
16384 (16 kHz) |
5 |
AD-box model MK2HS 'High-Speed' (no AIB mode, no Daisy-chain, not compatible with MK1 or MK2)
AD-box switch |
ActiView displays mode |
Sample-rate |
Pin channels + EX channels + Sensor channels |
0 |
10 |
4096 (4 kHz) |
256+8+7 |
1 |
11 |
8192 (8 kHz) |
128+8+7 |
2 |
12 |
8192 (8 kHz) |
256+8+7 |
3 |
13 |
16384 (16 kHz) |
128+8+7 |
4 |
4 |
2048 (2 kHz) |
256+8+7 |
5 |
5 |
4096 (4 kHz) |
128+8+7 |
6 |
6 |
8192 (8 kHz) |
64+8+7 |
7 |
7 |
16384 (16 kHz) |
32+8+7 |
8 |
- |
- |
- |
9 (ABR-mode) |
9 |
16384 (16 kHz) |
5 |
AD-box model MK1
AD-box switch |
Sample-rate |
Pin channels + EX channels + Sensor channels |
0 |
2048 (2 kHz) |
256+0+0 |
1 |
4096 (4 kHz) |
128+0+0 |
2 |
8192 (8 kHz) |
64+0+0 |
3 |
16384 (16 kHz) |
32+0+0 |
4 |
2048 (2 kHz) |
232+8+7 |
5 |
4096 (4 kHz) |
104+8+7 |
6 |
8192 (8 kHz) |
40+8+7 |
7 |
16384 (16 kHz) |
8+8+7 |
8 (AIB-mode) |
2048 (2 kHz) |
AIB-mode |
9 |
Reserved |
Reserved |
| Note: When an AIB is connected, the AD-Box should always be on SpeedMode 4 and the AIB always on SpeedMode 8. |
| The number of modules (hardware channels) which are installed in the system determine which EEG channels are able to display signals (upgrading to more channels is always possible at a later stage by simply inserting additional 8-channel modules). |
| So, if a customer buys the system with for example 96 channels, he will have : |
| - 96 operational channels on 2 kHz |
| - 96 operational channels on 4 kHz |
| - 64 operational channels on 8 kHz (channels 65-96 displayed as flat liners) |
- 32 operational channels on 16 kHz (channels 33-96 displayed as flat liners) |
| The BioSemi acquisition software (ActiView) can display and save a subgroup of the available channels at a given sample rate. |
| Also, the incoming data can be downsampled in software to reduce the file size in situations where sample rates less than 2 kHz are acceptable. Examples: |
| I Want to make a recording of 8 channels at 16 kHz sample rate: |
| - The ActiveTwo will sample 32 channels at 16 kHz. |
| - ActiView will display and save 8 channels at 16 kHz. |
| I Want to make a recording of 80 channels at 256 Hz sample rate: |
| - The ActiveTwo will sample 256 channels at 2 kHz. |
| - ActiView will display and save 80 channels at 256 Hz. |