Docs: Neuralynx System Setup

Description

Step-by-step instructions for setting up and connecting the Neuralynx recording system in the patient room

Requirements 

• Equipment: 
  • NLX recording system
  • Shielding fabric (3)
  • Masking tape
  • Grounding octopus 1 (white, for microelectrode)
  • Grounding octopus 2 (grey, for chet)
  • Impedance meter
  • Jumper cables (male/female)
  • Patient blue folder
  • Pens (2)

Preparing the Patient Area

1. Position Neuralynx cart to the right of patient bed beside the clinical Nihon-Kohden amplifier (avoid moving the NK amp if possible)
2. Connect NLX cart power cable to red wall outlet behind patient bed 
3. Connect NLX PC ethernet cable to ethernet port (labled “NLX”, located on the wall above patient bed and EKG monitor)
4. Move patient table and tray away from the bed and testing equipment
5. Position table with experimental laptop over the bed and adjust height if needed
6. Disconnect bed (cables with blue connectors) and leg compression machine 
   1. Ensure patient is in a comfortable position for testing before disconnecting the bed
7. Disconnect personal electronic devices (e.g. phone/laptop chargers)
8. Disconnect the IV pump machine CHARGER only (black power supply with green light)

IMPORTANT: Plug in IV pump charger if low battery and patient is receiving infusion at any point

Setting up Neuralynx

Macroelectrode Connection

NLX can record from up to 128 macrochannels (2 banks total, A and B; each bank= 64 channels)

1. Locate Bank A (1-64 chan, green connector) and B (65- 128 chan, purple connector) macro cables on clinical Nihon-Kohden amplifier
2. Locate NLX Bank A and B macro cables (located on the back of the NLX cart, hardwired into an adapter below headbox) and have them easily accessible
3. IMPORTANT: Ask the patient if they expect a seizure to occur within the next minute while we swap the NLX and NK macro cables (this will temporarily disrupt EEG acquisition)
4. Screenshot patient EEG prior to disconnection
5. Loosen screws on NK Bank A and B connectors from NK amp
6. Loosen screws on NLX Bank A and B connectors from NLX headboxes
7. Disconnect NK Bank A and B cables from the NK amplifier
8. Connect the NK Bank A cable to NLX Headbox A- A port
9. Connect the NK Bank B cable to NLX Headbox B- BCD port 
10. Connect NLX Bank A and B cables to the Bank A (1-64) and B (65-128) ports on NK amplifier 

Microelectrode Connection

NLX can record from up to 96 microchannels (3 banks total, A-C; each bank= 32 channels)

1. Insert IDC-10 (Behnke-Fried) microelectrode connectors in each sub-bank on IDC-10 NLX chets (sub-bank=individual slots with 10 pins)
2. Insert commercial (AdTech) microelectrode in each sub-bank on A9 NLX chets by aligning commercial micro metal contacts with metal pins on A9 chets (sub-bank= wings with holes for Adtech contacts)
3. Once contacts are aligned with rows of pins, close A9 chet wing (‘click’ sound)
4. Connect black tether cables to each NLX chet
5. Secure chets to L/R patient head with masking tape (avoid chet placement along midline and posterior area)

 ATLAS Hardware

Software

1. Open Pegasus
2. Under Subject ID, select ‘Create a New Subject’ and enter patient ID
3. Keep ‘DefaultSession’
4. Click ‘Select a Different Startup File’
5. Load patient configuration file (.cfg) 

Windows (C:)/Program Files/ Neuralynx/Pegasus/Configuration/ xxx_InitialGuess.cfg

6. Pegasus will save this config file for the patient you have entered
7. Select ‘Start Pegasus with last configuration file’ on Pegasus home for future recordings with the patient
8. Pegasus windows that you will need: 
   1. Acquisition System Status – start/stop Data Acquisition (ACQ) and Recording (REC)
   2. Micro Window 5000 ms – micro raw LFP (microchannels listed to the left)
   3. Macro window 5000 ms – macro raw LFP (macrochannels listed to the left)
   4. Spike Window 1- plots individual spikes detected on each microchannel
   5. Event Display- displays a log of TTL events
   6. Time Window 1- displays Events (TTL pulses) and Microphone channels
9. To create a Time Window if not automatically loaded by Pegasus, go to Window>Add Window> Time Window
10. To add channels to Time Window, go to Display> Add Plot(s) 
11. Select and add channels from list of Acquisition Entities
12. Close all other Pegasus windows
13. Stop Data Acquisition
14. Set path for new recording, go to Acquisition> Recording Options > Data Directory > Browse
15. Create experiment folder

DATA (E:)/ATLASData/DXXX/EXPX_Paradigm

16. Start Acquisition
17. Run TTL test- verify triggers are sent and appear on Events channel or Event Display
18. Check microphone signal- turn on microphone and connect mic to NLX headbox (see Equipment Check Protocol, Neuralynx section D)
19. Start Recording

Denoising 

1. Wrap chets with shielding fabric
2. Avoid tangling and bending of micro ribbon cables/AdTech pigtails, NK and NLX macro cables, NLX tether cables etc.
3. Keep NK and NLX cables off of floor and away from common sources of electrical noise (i.e. NLX power supply, NK amplifier)
4. Disconnect unnecessary electronic devices in patient room
5. Use external keyboard if laptop keyboard is introducing noise (occasionally observed with CNL mac 5)
6. Connect stimulators/other devices and NLX on different walls
7. Change references for individual channels via software (consult research team beforehand)

Pegasus > View > Acquisition Entities and Display Properties> Acquisition Entity Properties > Reference 

Important Notes:

• Never use scissors to remove or cut dressing, tape etc. on patient head
• Gently remove tape by hand
• Avoid use of excess tape as this adds weight to patient head and makes it difficult to access wires by research or clinical teams
• Unless uncomfortable for the patient or for clinical reasons, chets can remain on patient overnight 
• Always check proper chet placement after testing and before leaving patient