Human beings encounter various stressful situations every day at work, home, and school. Stress, if experienced at high levels and/or over an extended period, could lead to cardiovascular disease, cognitive dysfunction, and psychological disorders. Instead of electrode solutions, transdermal optical imaging (TOI) technology allows you to remotely evaluate changes in facial blood flow by using a digital video camera and provide an interesting medical framework.
What Exactly Is Transdermal Optical Imaging?
Human cardiovascular activities are fundamental biological indicators. Widely used in a variety of physiological and psychological activities, the research of human neurosciences entrust them with a series of measurement parameters. For example, during rest, cardiovascular activity is at the primary level. However, when people are under acute stress, their cardiovascular activity increases, whereas when they are concentrating, their cardiovascular activity decreases.
The assessment of stress conditions is based on the analysis of psychometric and biometric data. The latter can provide an objective evaluation through the use of electrodes or sensors placed on the body. One of the methods is to get signals of cardiovascular activity from under the skin through optical sensors. Transdermal optical imaging overcomes the limits of current methodologies using a digital video camera to acquire facial images without contact and remotely extract cardiovascular changes in the form of images. This technique exploits the reflection of light through the influence of chromophores, mainly haemoglobin and melanin, which have different chromatic responses. The re-emitted light can be captured externally by optical sensors, from which the changes in blood flow under the skin can be extracted.
An AI system can identify differences in response from separate regions of haemoglobin to define images it sees, relative to the change of some parameters. The face is ideal for analyzing changes in blood flow, as it is rich in blood vessels, allowing us to obtain information without contact and remotely.
Figure 1. TOI acquisition scheme. The light beam rebounds through different skin tissues. On the right an example of an image of a face.
Digging Deeper Into the Technology
Optical imaging uses light to interrogate cellular and molecular function in the living body, as well as in animal and plant tissue. The information ultimately derives from the composition of the tissue and the biomolecular processes. Images are generated using light photons in the wavelength range from ultraviolet to near infrared.
Some examples of optical imaging technology include:
- Use of specific fluorescent agents and fluorescence imaging to quantify in biological changes in vivo
- Use of optical imaging to monitor various biological events, such as the development of tumours and metastases.
Children and TOI
Transdermal optical imaging (TOI) is a system that includes a video processing unit based on a video camera and software, which provides a set of pixels relative to changes in haemoglobin concentration.
One of the problems encountered in educating children is that they are not always taught in the ways they learn. With the use of the TOI, professionals could gain an understanding of each child to determine stress levels when using different teaching methods. Furthermore, a therapist would be able to see recurrent moods in children in various situations to get a better idea of what the child might feel at home or in school settings.
Image courtesy of Pixabay.
AI and Deep Learning
The technology can instantly detect the flow of blood on the face and works in most natural lighting situations with any type of digital video camera. First, video images are captured from a video camera. Subsequently, using transdermal software, it is possible to analyze changes in blood flow under the skin.
Changes in blood flow are associated with physiological and emotional phenomena. Using the data of various people who experience emotions, it is possible to define emotional models based on different situations of blood flow to discover happiness, sadness, fear, and so on.
The algorithm used in these cases will have to recognize certain faces and, at the same time, learn from situations by using AI techniques—or have a memory of what has been done to use it in the upcoming acquisitions of artificial vision effectively.
Machine learning is mostly a road to the implementation of artificial intelligence. It’s a kind of AI subgroup that focuses on the ability of machines to receive a set of data and learn on their own, modifying the algorithms as they receive more information about what they are processing. Very often, the terms AI and machine learning (ML) have been used interchangeably.
Machine learning automates the construction of the analytical model. Use methods of neural networks, statistical models and operational research to find information hidden in the data. Thus, with all the images encountered in transdermal optical imaging, the system at hand is able to make conclusions based on those data points.
Conclusion
Facial cardiovascular activities are associated with various independent components which reflect different dynamics of changes in the blood flow of the face. Experimental results suggest that chromatic differential dynamics can be used to study physiological and psychological activities in the humans. Because this technology proves so useful in so many different situations, it is imperative that we pursue its study and implementation.
All in all, the potential of transdermal optical imaging technology with AI solutions represents a new, low-cost, and non-invasive methodology of neuroscience.
Featured image courtesy of the University of Toronto.
