Carolina NeuLog Electrocardiogram (ECG) - Manual

NEULOG ELECTROCARDIOGRAM SENSOR GUIDE
Neulog electrocardiogram Sensor
NUL-218
Carolina # 369647
The NeuLog electrocardiogram sensor can be used for any science experiment or
activity that can utilize heartbeat data such as in the fields of: Biology, Physiology,
Human medicine, Psychology, etc.
An electrocardiogram is a very commonly used medical device which measures and
graphs the heart’s electrical activity. Every single heartbeat is a very complex event
which involves many anatomical locations undergoing changes in their electrical
charges. A depolarizing cascade event originates in the Sinoatrial Node, which is
often referred to as the natural pacemaker, and travels throughout the rest of the
heart.
The sensor comes pre-calibrated so you can start experimentation right out of the box
using any of the following guides.
Just a few of the thousands of possible experimental subjects that can be done with
the NUL-218 sensors are: electrical impulses, heart rate monitoring, human
physiology, muscle physiology, heart rate changes to stimuli, and many more.
The ECG sensor uses the following unit of measure:
 Arbitrary analog units (Arb): An arbitrary unit to demonstrate waves,
frequencies, and periods. Therefore what you will see on the Y-axis is
signal intensity, while the X-axis shows time.
Electrocardiograms:
The heart undergoes a very complex process of electrical activity; this is the basis for
how electrocardiograms work. As the heart’s muscles contract, the cells are
electrically depolarized which causes a cascade of depolarization to flow across the
heart
– contracting the heart’s muscle fibers.
During a heartbeat a very complex series of events happens which begins with the
cells resting potential at roughly -90mV (millivolts). The hearts Sinoatrial Node begins
the cascade by depolarizing
– creating an electrical current. The electrical signal
travels to the right atrium and almost immediately to the left atrium. Because the atria
and the ventricles are insulated from each other by a special type of cell which acts as
an electrical insulator, the signal is picked up in another cluster of cells called the
Atrioventricular Node located in the right atria. The signal is carried by a special type
of fibers - the Bundle of His into the ventricles. Purkinje Fibers rapidly spread the
electrical depolarization cascade throughout the ventricles. The entire event takes
some time to complete. The graph is a visual demonstration of the heart’s relative
charge at any given point during heartbeats.
The electrical current is measured on the skin using conducting leads and converted
into a graphic that is very standard and reproducible.
P: Contraction of atria
Q: Initial depolarization of the ventricle
R: Early depolarization of the ventricles
S: Late depolarization of the ventricles
T: Repolarization of the ventricles
U: Often hidden by the T wave
– this wave has anunknown origin
This graph represents one complete heart beat from depolarization of the Sinoatrial
Node to repolarization of the ventricles.
Connecting to the ECG sensor:
The NeuLog electrocardiogram sensor uses three reusable clip leads for easy
connection to the arms. Each pair of leads (red + yellow, red + black, black + yellow)
measure the heart’s electrical fluctuations and are all compared against one another.