Janis's notes from Karin and Bernhard's tutorial in November 2016
Cleaning the Eye Coils
- The coils can sit indefinitely in saline solution, which is also used to rinse them.
- The coils should be cleaned before and after experiments - before especially if they have not been used in a while. It's a good idea to soak them in saline solution before an experiment because its easier to insert them into the eye when wet.
- Clean the coils with the hydrogen peroxide solution. To mark which cup is the peroxide, but a piece of tape over it (so that it looks different from the saline solution. The coils should only be in there for a few minutes otherwise they start dissolving. (max time 10-15 minutes)
- Use a q tip to wipe off any mucus - gently.
- Rinse the coils twice in saline solution - each time in a different fresh solution.
- To remove and store: Dry them off carefully with a facial tissue and place them carefully in a case so that the wire does not become a knot. The case does not need to be fully closed.
- To save for a day or for another subject: Just let them soak in the saline solution for a while.
Connecting the coils
- Before an experiment test the resistance of the connectors. They should be around 19ohms but 15-25 is fine. If it's too far off the connector is probably about to break.
- There are 8 channels to connect to. 5 of them are usable (the other 3 do x y z?).
- There's a chart on the wall that maps the connector numbers 1-8 to channel numbers (0-7). Make sure you know which one you are referring to - the software using channel numbers.
- Be gentle when connecting and disconnecting the connectors. If these break they're hard to fix.
Setup
- Turn on the amplifiers. This is just a switch in an adapter under the amplifiers (farthest room from the entrance). Don't touch anything else in this setup.
- Once the amplifiers are on there should be a green LED and 0.0 display on the PCB in the other room.
- (Turning on the computer/CBP) - I recorded this in the video but didn't take notes.
Coil Calibration
- Open up hyper terminal. Don't connect to a modem (just skip / cancel things).
- Open BOSS_Terminal_COM4.ht - connection settings should now appear at the bottom of the terminal
- Press ENTER so that the system knows to connect
not sure what all this is: [----- OFF Meas0 ...]
-----: 5 channels, not calibrated
- OFF or ON is system status
Meas0 is a counter for data -> must be a 0 to start
- Calibrate one channel at a time - it's easier and probably more accurate
- In the terminal: "l-4" calibrates channel 4 alone. To do multiple channels exclude -
- Make sure coil is in starting position before pressing "y" to start
- Wait for all 0s to become 1s (collecting 18 directions). It should stop automatically.
- Person in the field: turn the coil 360 degrees in both directions around all 3 axes. To do an eye coil, just tape it into a tray. Do the calibration near to where the subjects actual head will be.
- To cancel the calibration just use the field "ON" or "OFF" buttons since the software won't take keyboard input while it is receiving data
- Software returns orientation vectors (unit vector) [R G B] or [x y z] - coils are color labeled for clarity [12kHz, 16 kHz, 20kHz].
Recording
There is still a work around since the receiver software has not been written by Ruei yet. So this is likely to change in the near future.
- To start and stop recording press the green button (it's on the long cable). The yellow light will be flashing during a recording. This button turns the data stream on and off.
- (Hack) to record data, change some settings in the hyperterminal. Tania took pictures of the 4 commands that need to happen:
- V10
s8 -> 500Hz (default s4, 1000Hz)
- V116
s-1 -> ASCII characters (default s0, binary)
- Make sure to delete the CAPTURE file if one exists before starting
- Open a second hyperterminal, open BOSS_..._COM7.ht
- Start a recording / stop a recording
- Follow German commands to save the data to the CAPTURE file
- Cut and paste this file elsewhere to save it
Matlab read recorded data
Txt2Mat.m to read the capture file
- It plots rob components as orientation vectors (unit vectors - or rather all of these vectors should have the same length)
- There is code to convert these to angles but it needs to be checked and refine so we'll get in touch with Karin when it is ready
Other / Miscellaneous
- Even rapid hand movements can affect the data so tell the subject to move as little as possible
- Noise should be less than 1 arc in (RMS)