
3B SCIENTIFIC
Instruction sheet 
04/09 Hh 
®
 PHYSICS 
ECG/EMG Box  U11396 
1 ECG/EMG box 
2 miniDIN connecting cable 
3 Limb attachment leads 
4 ECG attachment electrodes 
1. Safety instructions 
The ECG/EMG box is only suitable for educational 
purposes. The measurement data and curves 
obtained with it must never be used for assessing the 
state of health of a person. 
•  Do not use the ECG/EMG box for diagnostic 
purposes. 
•  Do not use the ECG/EMG box for monitoring the 
effects of therapeutic treatments. 
•  The ECG/EMG box must not be opened or 
interfered with under any circumstances. 
•  Do not operate the ECG/EMG box near heart 
pacemakers or other electrical stimulation or 
therapeutic devices. 
•  Only connect the ECG/EMG box to one test 
person at any time. 
The ECG/EMG box is constructed in accordance with 
the current safety requirements for “Protection Class 
II, Classification BF (body float)”! 
•  An instrument configuration consisting of the 
ECG/EMG box and the 3B NETlog 
be operated with a PC that conforms to the 
current CE regulations! 
TM
 unit may only 
2. Description 
Sensor box for the measurement of an 
electrocardiogram (ECG) on the skeletal musculature 
using the three standard Einthoven limb leads I, II 
and III: 
Lead I: from right arm to left arm; 
Lead II: from right arm to left leg; 
Lead III: from left arm to left leg. 
The three leads can be selected by push-button and 
the choice is indicated by an LED. 
The equipment works by measuring the changes in 
skin surface potential caused by contraction of the 
heart. 
The action potentials of muscles in both relaxed and 
energised states can also be measured 
(electromyogram, EMG). 
The sensor box is detected automatically by the 3B 
TM
NETlog
 unit. 
1 

3. Equipment supplied 
6. Applications 
1 ECG/EMG box 
1 Limb attachment leads, 4-position (right arm, left 
arm, left leg, right leg), with push-button contacts, 
length 1.50 m 
2 Packs (60 in each) of ECG attachment electrodes 
F55, Ag/AgCl, with gel pre-applied 
1 miniDIN connecting cable, 8-pin, 1 m long 
1 Instruction sheet for U11396 
4. Technical data 
Input resistance:  > 10 MΩ  
Output voltage:  max. ± 1 V 
Blocked frequency:  50 - 60 Hz 
5. Operation 
Important: When attaching the limb leads (“patient 
leads”), try to avoid crossing them over, and ensure 
that there are no current-carrying conductors 
nearby. 
Vigorous movements by the person being tested can 
cause artefacts (disturbances) in the recorded curves. 
The person should remain lying back in a quiet and 
relaxed state. 
•  To prepare for recording the ECG, attach one 
electrode each (4 altogether) to the inner 
surfaces of both forearms and on the inner 
surfaces of both calves. 
•  Connect the limb leads to the ECG electrodes, 
with the correct colour identifications: 
  RED for the right forearm (right arm), YELLOW 
for the left forearm (left arm), GREEN for the left calf 
(left leg), and BLACK for the right calf (see Fig. 1). 
•  Using the miniDIN connecting cable, connect the 
ECG/EMG box to one of the two analog inputs U
B
or U
 of the 3B NETlogTM unit, whichever is 
in
A
in
preferred. 
•  Switch on the 3B NETlog
TM
 unit and wait for the 
box to be detected automatically ("Probe 
Detect"). 
•  Place the ECG/EMG box near the test person. 
•  By means of the push-button on the box, choose 
the required standard lead I, II or III. 
•  For recording the EMG (electromyogram), attach 
four electrodes to the arm of the test person as 
shown in Fig. 3: 
RED to the inner surface of the lower part of the 
left forearm, YELLOW to the inner surface of the 
upper part of the left forearm, GREEN and 
BLACK to the outer surface of the left forearm. 
•  Select the EMG mode by pressing the button "I" 
for about 2 seconds. 
Recording an ECG in a relaxed state with the three 
standard EINTHOVEN leads. 
Studying the P, Q, R, S, T and U waveforms. 
Recording an ECG after light physical activity. 
Investigating the effects of different body postures 
on the ECG curves. 
Investigating the effects of external influences 
(excitement, fright) on an ECG. 
Determining pulse rate from the ECG curves. 
Recording an EMG (electromyogram) produced by 
muscle contractions; measuring the electric 
potentials for involuntary movements of relaxed 
muscular regions. 
7. Sample experiments 
1. Recording the ECG (electrocardiogram) of a 
person 
Equipment required: 
1 3B NETlog 
1 3B NETlab
TM
 unit  U11300 
TM
 software installation U11310 
1 ECG/EMG box     U11396 
•  Prepare the experiment as shown in Fig. 1. 
•  In 3B NETlab
TM
, open the application program 
(template) for the ECG experiment using the 
ECG/EMG box. 
•  Start the template and record the curve for the 
chosen ECG variant (in this case, relaxed-state 
ECG with Einthoven standard lead I, see Fig. 2). 
•  Evaluate the ECG curve in accordance with the 
information about basic principles in the 
template. 
•  Determine the pulse rate of the person being 
tested. 
Important
: If the ECG just recorded does not 
completely resemble the example provided, this is 
not a cause for concern. Every person can show 
differences from the norm; even healthy hearts show 
such variations. The precise interpretation of an ECG 
requires much medical experience. This ECG/EMG 
box is not an instrument for diagnoses of that kind. 
2. Recording the EMG (electromyogram) of a 
person 
Equipment required: 
1 3B NETlog 
1 3B NETlab
TM
 unit  U11300 
TM
 software installation U11310 
1 ECG/EMG box     U11396 
•  Set up the experiment as shown in Fig. 3. 
2 

•  In 3B NETlab
TM
, open the application program 
(template) for the EMG experiment using the 
ECG/EMG box. 
•  Start the template and record the 
electromyogram curve (Fig. 4). 
•  Evaluate the EMG curve in accordance with the 
information about basic principles in the 
template. 
Note
: In the practice of medical “electrodiagnostics”, 
an EMG yields information about diseases of the 
nerve and muscle cells (neuropathy and myopathy). 
In “biomechanics” the relationships between the 
frequencies and amplitudes of the electrical signals 
and the performance of muscles are investigated, for 
example in order to optimise the movements of an 
athlete or sportsperson. 
Fig. 1 Recording the ECG of a person 
Fig. 2 A relaxed-state ECG recorded using Einthoven standard lead I and displayed on the screen in 3B NETlab
TM
 (U11310) 
3 

Fig. 3 Recording an electromyogram of the left forearm of a person 
Fig. 4 EMG of muscular contractions of the left forearm; effect of switching between relaxed and active phases 
3B Scientific GmbH • Rudorffweg 8 • 21031 Hamburg • Germany • www.3bscientific.com 
Subject to technical amendments 
       © Copyright 2009 3B Scientific GmbH