PASCO PS-2111 EKG Sensor - Manual (Page 2)

®
E K G S e n s o r PS- 2111
2
Heart rate and voltage measurements are acquired at the default
rate of 200 samples per second. You can lower the sample rate to
50 samples per second; however for best results, use the default
rate.
About the Electrocardiogram
Figure 2
To see the electrocardiogram (Figure 2), display voltage versus
time in a graph. One part of a typical electrocardiogram is a ‘flat
line’ or trace indicating no detectable electrical activity. This line
is called the isoelectric line. Deviation from the isoelectric line
indicates electrical activity of the heart muscles. The sensor’s
Voltage measurement represents this deviation.
The first deviation from the isoelectric line in a typical EKG is an
upward pulse followed by a return to the isoelectric line. This is
called the P wave. This wave is caused by the depolarization of
the atria and is associated with the contraction of the atria.
After a return to the isoelectric line there is a short delay while
the heart’s atrioventricular (AV) node depolarizes and sends a
signal along the atrioventricular bundle of conducting fibers (the
bundle of his) to the Purkinje fibers, which bring depolarization
to all parts of the ventricles almost simultaneously.
After the AV node depolarizes there is a downward pulse called
the Q wave. Shortly after the Q wave there is a rapid upswing of
the line called the R wave followed by a strong downswing of the
line called the S wave and then a return to the isoelectric line.
These three waves together are called the QRS complex. This
complex is caused by the depolarization of the ventricles and is
associated the with the contraction of the ventricles.
After a short period the sodium and calcium ions that have been
involved in the contraction migrate back to their original location
in a process that involves potassium ions and the sodium-potas-
sium pump. The movement of these ions generates an upward
wave that then returns to the isoelectric line. This upward pulse is
called the T wave and indicates repolarization of the ventricles.
The sequence from P wave to T wave represents one heart cycle.
The number of such cycles in a minute is called the heart rate and
is typically 70-80 cycles (or beats) per minute at rest.
Safety
• The EKG Sensor is for educational use only.
• Placement of the electrode patches on the body provides an
excellent path for current flow. Do not connect anything to
the electrode patches other than the EKG Sensor as
described in this instruction sheet.
The sensor’s circuitry protects the test subject in two ways: The
sensor signal is transmitted through an optical-isolation circuit
and power for the sensor is transferred through an isolation trans-
former. The circuitry protects against accidental overvoltages of
up to 4,000 volts.
Specifications
Technical Support
For assistance with any PASCO product, contact PASCO at:
For more information about the EKG Sensor and the latest revi-
sion of this Instruction Sheet, visit:
www.pasco.com/go?PS-2111
Limited Warranty For a description of the product warranty, see the
PASCO catalog. Copyright The PASCO scientific 012-08007D EKG
Sensor Instruction Sheet is copyrighted with all rights reserved. Permis-
sion is granted to non-profit educational institutions for reproduction of any
part of this manual, providing the reproductions are used only in their labo-
ratories and classrooms, and are not sold for profit. Reproduction under
any other circumstances, without the written consent of PASCO scientific,
is prohibited.
Trademarks PASCO, PASCO scientific, and PASPORT
are trademarks or registered trademarks of PASCO scientific, in the
United States and/or in other countries. All other brands, products, or ser-
vice names are or may be trademarks or service marks of, and are used to
identify, products or services of, their respective owners. For more infor-
mation visit www.pasco.com/legal.
T wave
P wave
QRS complex
Voltage range 0 mV to 4.5 mV
Voltage resolution 4.5 V
Sample Rate 200 samples per second
Heart rate range 47 to 250 beats per minute
Heart rate resolution 1 beat per minute
Address: PASCO scientific
10101 Foothills Blvd.
Roseville, CA 95747-7100
Phone: 916-786-3800 (worldwide)
800-772-8700 (U.S.)
Fax: 916-786-7565
Web: www.pasco.com
Email: [email protected]