BT48i Heart Rate User’s Guide
|
3
the heart rate by analyzing the time between peaks, or counting the number of
beats per minute by using the heart rate sensor as counter with a threshold of e.g.
35%.
Heart rate varies between individuals. At rest, an adult man has an average pulse of
72 per minute. Athletes normally have a lower heart rate than less active people.
Children have a higher heart rate (approx. 90 beats per minute), but also show
large variations. The heart rate rises during exercise and returns slowly to the rest
frequency after exercise. The rate at which the pulse returns to normal can be used
as an indication of fitness.
Notes:
•
The Heart rate sensor cannot be used during exercises. The body’s movement
would cause shifting of the ear clip and erroneous readings.
•
The ear and clip should be shaded from strong light.
•
The Heart rate sensor is not appropriate for medical or research applications.
Specifically, it may not be used for patient diagnosis.
Sensor recognition
The Heart rate sensor has a memory chip (EEPROM) with information about the
sensor: its name, measured quantity, unit and calibration. Through a simple
protocol this information is read by the CMA interfaces and the sensor is
automatically recognized when it is connected to these interfaces.
If your Heart rate sensor is not automatically detected by an interface you have to
manually set up your sensor by selecting it from the Coach Sensor Library.
Calibration
The CMA Heart rate sensor BT48i is supplied calibrated. The output of the Heart
rate sensor is linear with respect to voltage. The supplied calibration function is:
I(%) = 20 * V
out
(V)
The CMA Coach program allows selecting between the calibration supplied by the
sensor memory (EEPROM) or the calibration stored in the Coach Sensor Library.
Suggested experiments
•
Measurements of the heart rate of different individuals.
•
Measurements of the heart rate before and after exercises.
•
Measurements of the recovery time: how fast a person's heart rate returns to
its normal performance after exercise.
•
Measurements of the heart rate before and after drinking coffee (or Coca-Cola).
•
Simultaneous measurements of heart rate, EKG and heart sounds with sound
sensor to register heart tones.
