AD
INSTRUMENTS
LTS2020 Finger Pulse Sensor
Lt Sensors Series
Description
The Lt Sensors Finger Pulse Sensor uses a piezo-electric
element to convert force applied to the active surface of
the transducer into an electrical analog signal.
Operation
The Sensor is kept in place using a hook-and-loop
fastener around the finger when measuring finger
pulse. Some repositioning may be required to obtain the
best signal. If there are difficulties in obtaining a good
signal, the following actions may be followed.
•
Adjusting the placement of the sensor on the finger
•
Adjusting the tightness of the strap
•
Warming up the subject’s hands
Blood pressure changes will change the finger circumference (expansion and contraction),
which will then change the force applied to the active surface of the transducer. Therefore,
changes in the electrical analog signal correspond to these force changes and can then
be used to determine heart rate. The typical output is 50–200 mV (can reach as high as
500 mV).
NOTE: The transducer is sensitive to movement. To avoid large motion or artifacts
and obtain good recordings, keep the transducer still. The thumb or the middle finger
usually provides a good pulse measurement.
To use the Finger Pulse Sensor, plug the sensor into the USB port of a laptop or desktop
computer, with a Windows operating system. Alternatively, plug the sensor into a USB
hub connected to that computer. A green LED on the connector housing indicates the
transducer is receiving power and is ready for use.
