TDT Medusa4Z User manual

Important: The Medusa4Z has a recessed slide power switch on the left
side and ships with this switch OFF. Switch this ONduring initial setup.
Power Supply: 6 V –16 V DC, > 1 A, tip polarity is irrelevant
On/Off (Reset): This should be left ON once you set the Medusa4Z.
Turning it to OFF will RESET the unit to factory defaults. The switch is
recessed so the user must intentionally try to move the switch.
Optical: Fiber optic port for connecting the Medusa4Z to the base
station. See Hardware setup for more details
GND –Ch 1: Electrodes can be plugged directly into the 1.5 mm
touchproof connectors on the side, which are depicted on the left.
How do I change my settings? Setup → Options → Set
1. Press Setup to cycle through the settings categories
2. Press Option to cycle through that categories sub-
options
3. Whichever value Option is left on will be the setting
This fast fact sheet provides basic
information for the Medusa4Z Bioamp. See
the System 3 Manual for more information.
Hardware Setup
Turn unit on/off; Return to
home; Reset power down timer
View channel
electrode
impedance
View Ref electrode impedance
Change selected setting
Cycle through available settings
Your First Steps to Recording
1. Set OFF (Reset) switch to ON
2. Press Power
3. Plug in fiber optics
4. Set desired sampling frequency
5. Go*
Use the provided fiber optic pair (black cable, white connectors) to
connect the OPTICAL port on the preamplifier to the OPTICAL INport
on the base station as shown to the right. Connect one end into the
RZ with the raised rectangle side up and connect the other end into
the Medusa4Z with the V-shaped groove up.
*This will run the Medusa4Z at factory settings.
DEFAULT Settings:
Active Channels:
>> Single <<
Sample Freq:
>> System Rate <<
Impedance Frq:
>> 1kHz <<
Highpass Filter:
>> 3Hz <<
Auto Shutdown:
>> Never <<
Setup → Options → Set
Setup → Options → Set

Setup
Option
Notes
Active Channels
Single or Four Channel
In single channel mode, unused channels are shorted to ground
Sample Freq
3 kHz (1500), 6 kHz (3 kHz),
12 kHz (6 kHz), System Rate
System Rate is the processor’s rate up to 25kHz
The number in ( ) represents the frequency content that can be
acquired at the Sample Freq without aliasing.
Impedance Frq
100 Hz, 300 Hz, 500 Hz, 1 kHz
This is the probe frequency for checking the impedance of
electrodes
Highpass Filter
Off, 1 Hz, 3 Hz
‘Off’ is a 0.1 Hz filter. There is a fixed 0.3Hz high pass analog
filter on the inputs
Auto Shutdown
Never, 1 hour, 3 hours, 5 hours
After a period of inactivity, the Medusa4Z will shut itself off to
preserve power. Press Power to re-energize after Auto Shutdown.
Maximum Voltage In
+/- 10 mV
S/N (typical)
80 dB
Input Referred Noise
(μVrms)
Depends on Medusa4Z sample rate and electrode impedance
Medusa4Z Rate
Shorted
3 kOhm
10 kOhm
3 kHz
0.15
0.3
0.5
6 kHz
0.25
0.4
0.7
12 kHz
0.3
0.6
1.0
25 kHz
0.4
0.9
1.4
Sample Delay
Dependent on Medusa4Z and RZ processor sample rates
(RZ at 25 kHz)
(RZ at 12 kHz)
(RZ at 6 kHz)
Medusa4Z rate
Samples
Samples
Samples
25 kHz
24
N/A
N/A
12 kHz
42
24
N/A
6 kHz
76
42
24
3 kHz
146
76
42
Battery
Li-Poly Battery 5 Ah capacity. Single channel mode, 30 hours between charges. Four
channel mode, 24 hours between charges. 1000 cycles of charging, not removable by user.
Medusa4Z_Input
Output-1
Output-2
Output-3
Output-4
In RPvdsEx (OpenEx, Synapse)
Use the Medusa4Z_Input Macro. Set the number of desired channels.
The macro does not account for sample delays.
In BioSigRZ:
Setup →Acquisition →Setup Inputs →Source →
Medusa4Z
To avoid sample delays in your data trace, you must
match acquisition rate in BioSigRZ to the Medusa4Z
hardware Sample Freq (cycle Setup →Sample Freq
→cycle Option). 25 kHz in BioSigRZ will be
System Rate on Medusa4Z.
* 12kHz recommended for ABRs
Note: This software setting does not set the hardware
sampling rate.
Important: You must use TDT Software (Drivers/RPvdsEx or BioSigRZ)
version 92 or later to use the Medusa4Z
Software Configuration