AFFECTIVE COMPUTING
Uses and Examples
The Galvactivator
The galvactivator is a wearable device on the hand made in MIT that detects the skin conductivity of the user and uses an LED to as an indicator for the emotions. Electrodes are placed at different position compared to the traditional placement as shown in the diagram below. The glove contains an amplifier that allows the LED to light up when there is a signal. The LED allows the user and people around to know their physiological responses to certain activities. The galvactivator is an example of a device which can detect arousal emotions such as excitement or stress.
Figure 2 From R.W. Picard and J. Scheirer (2001). The Galvactivator: A Glove that Senses and Communicates Skin Conductivity. MIT Media Laboratory
Figure 1 From Hernandez J., Li Y., Rehg J., Picard R. W. (2014) BioGlass: Physiological parameter estimation using a head-mounted wearable device. MIT Media Laboratory
BioGlass
The bioglass consist of different sensors embedded in Google Glass. The creator of the bioglass actually developed new methods using the Glass’s accelerometer, gyroscope and camera to calculate the pulse and respiratory rates. Algorithms were also developed to extract the physiological signals from the sensors. A band-pass filter (similar to using a low-pass and high-pass filter together) with cut-off frequencies of 0.75 and 2.5Hz was used to smooth out the final wave.
Polygraph
Polygraph (also known as a lie detector) measures the stress of the subject using the change in blood pressure and pulse rate, skin conductance, and respiratory rate. The theory is that the physiological signals changes whenever the person is lying (i.e. under stress). It use methods similar to the ones mentioned in this website to detect these physiological responses. Some of the newer techniques similar to the traditional polygraph are the use of EEG or fMRI (which also show the blood flow to the brain) which can record the brain-wave responses during an interrogation. Although these are more invasive, it is also more reliable and accurate.
