Service manual

Revision 2/18/05 3 - 57
Hardware Description
Patient Signal Path - Endeavor CR
The Patient Signal Path functional unit is a Nicolet-
unique part of the Endeavor CR. The Least Replaceable
Units (LRUs) are designed and manufactured by
VIASYS Healthcare.
Hardware Components
The signal path functional unit consists of the following
components:
• 16-Channel AES Amplifier
• Headbox HB-1
• Headbox HB-2
Amplifier Block Diagram
The block diagram shows the functional components
contained within the amplifier housing.
Electrodes from the patient plug into one of two
headboxes, which are in turn connected to the amplifier.
Crosspoint switches in the amplifier route the electrode
signals to any of the sixteen amplifier channels where
they are amplified by a factor of 100, 1000 or 10000.
The signals also flow through a High-Pass Filter (HPF)
and a Low-Pass Filter (LPF) where selective frequency
bands are attenuated.
ENDEAVOR
Control Logic
ADC2
ADC1
Crosspoint Switches
Mux A
Mux B
USB
Interface
DSP and
Control
Logic
DC-DC
Converter
Opto-Isolators
Isolation
Barrier
+15V
I+8V
I+15V
I-15V
ENDEAVOR
Ch1 Hybrid
Ch2 Hybrid
Ch7 Hybrid
Ch8 Hybrid
Ch9 Hybrid
Ch10 Hybrid
Ch11 Hybrid
Ch12 Hybrid
Ch3 Hybrid
Ch4 Hybrid
Ch5 Hybrid
Ch6 Hybrid
Ch13 Hybrid
Ch14 Hybrid
Ch15 Hybrid
Ch16 Hybrid
Control
Cal/Z
Source
Ext
Cal
16-Channel Amplifier Block Diagram