Other Physiological Responses

There are other physiological responses that we could also detect. Such response would include heartbeat/heart rate, skin temperature, brain activity, blood pressure, and respiration. Blood Volume pulse and Skin conductance are only some of the more common signals used in detecting the emotional state of the user. Listed below are how some of these other responses can be detected.

Heart Rate

The electrical signals that causes the contraction of the heart can be detected using an electrocardiogram (ECG) which captures the electrical activity on the surface of the skin. ECG is a more precise measurement of the heart rate than PPG but is usually required to have the electrodes attached to the chest, arms and legs.

Skin Temperature

Skin temperature can easily be measured using a feedback thermometer that uses a thermistor. The thermometer can be attached to most part of the body but usually to fingers or toes.

Blood Pressure

Blood pressure can be used as a measure of emotional stress. However, the techniques used to measure blood pressure usually require the subject to stay still and is uncomfortable. Long term use of some of the smaller systems over a long period of time can also cause smaller surface blood vessels to be damaged.

Respiration

Respiration are usually a good indicator of which main dimension of emotion the subject is feeling (e.g. excited or sleepy, much like skin conductance). In affective computing, a good way to measure respiration would be chest expansion using a pneumograph. This is placed around the chest and will measure the expansion and contraction of the chest and also the respiratory rate.