Heart Rate sensor

The Heart Rate sensor BT48i provides a simple way to study the heart's function. Unlike an electrocardiograph (EKG), which monitors the electrical signal of the heart, this sensor monitors the flow of blood through the veins. As the heart forces blood through the blood vessels, the amount of blood changes with time. The sensor measures the light level transmitted through the vascular tissue and the corresponding variations in light intensities that occur as the blood volume changes in the tissue. The measured signal is amplified, inverted and filtered. The sensor is equipped with an amplification knob that allows amplifying the signal when it is too weak. The clip can be used on an ear lobe, a fingertip or on the web of skin between the thumb and index finger.

Examples of experiments
• Measurements of the heart rate of different individuals.
• Measurements of the heart rate before and after exercises.
• Measurements of the recovery rate: how fast a person's heart rate returns to its normal performance after exercise.
• Measurements of the heart rate before and after eating or drinking coffee (or Coca-Cola).
• Simultaneous measurements of heart rate, EKG and heart sounds with sound sensor to register heart tones.

The CMA Heart Rate sensor can be directly connected to the analog BT inputs of the CMA interfaces.
Attention: The sensor cable BT - IEEE1394 needed to connect the sensor to an interface is not supplied with the sensor and has to be purchased separately (CMA Art. Nr BTsc_1).

Technical specifications of the sensor are described in its User's guide.