GSR indicating illness



In the middle of the best flu season many of us go to work feeling ill. It might be that the thermometer does not indicate fever, or even when it does, the obligations seem unavoidable.

The Moodmetric Ring is a sensor of GSR (galvanic skin response – or skin conductivity). It gives an interesting additional insight to measuring illness. GSR tells about emotional intensity level, the fight or flight reaction. The something you´d need to fight against, might also come from inside of you. When you are ill, the Moodmetric index gives a higher score than you usually get, even if you stay in bed. If you try to work, even just sitting at your laptop, the figures can be really high.

One of our customers sent us the below picture: She was ill, no fever but the general feeling of profound tiredness, head and muscle ache. She had the chance to stay at home and lie on the couch for the day. Still the MoodFlower looks like having been in hectic meetings for the whole day.


The next day for her was like this:


She felt better and was doing some light work like proof reading. With higher figures only between 9-10am, the day is seemingly calmer. Staying home for two days was a good decision, on Thursday she was back at the office energetic as ever.

GSR can be an indicator of both an acute pain, or an illness that is not so clear to describe. Self-awareness plays a big role in getting cured faster. Am I fit to work already today? The Moodmetric Ring can support in acknowledging that now it is best for me to take it easy.




Assembling the Rings

Emotion load indication through electrodermal activity or skin conductance measurement is a rising trend in the modern wearable technology. Most manufacturers use the word stress as a synonym for emotional load.
Wearables are typically forced to use dry skin electrodes in varying conditions, with movement present. Ideally the system should be able to detect, interpret and visualize underlying electrodermal activity changes caused by autonomous nervous system reactions.
Typically the following challenges are present:
• Dry and sweaty hands produce autonomic responses with significantly different amplitudes
• Different people produce significantly different response amplitudes
• Analysis is subject to constant motion artifacts
The Moodmetric algorithm is developed to produce higher lever emotional information of the wearer, based on the raw conductivity signal received.


The first Moodmetric rings have been produced. The ring is improved version of the beta sample, that has been in user testing since October 2014. The electronics manufacturing and 3D-printing of the covers of the new version was made in August 2015. The stone assembly could now be completed:



The two steel rings with an insulation in between is the actual sensor needed to detect the changes in skin conductivity. The ring comes in four sizes: US (6.5, 8, 10 and 12.5), EU (17, 18,5, 20 and 22 mm). It is exchangeable which enables several users to the same stone. This reduces cost but note: excessive swapping causes the snaps to wear out.


The final product is small and lightweight. It connects with the Moodmetric app automatically and displays your emotional intensity real-time.


What is moodtech? – Science behind Moodmetric

Moodmetric measures the electrodermal activity (EDA) of the skin, which is widely adopted in psychological research 1. EDA is generated by activity of the sweat glands.  Moodmetric measures the palmar skin on your finger. The palmar skin is the recommended EDA measurement location, since it has the highest sweat gland density2.

The unconscious actions of the human body are regulated by the autonomic nervous system. It consists of the sympathetic part and the parasympathetic part. The parasympathetic part controls the body’s rest-and-digest functions and the sympathetic part controls fight-or-flight reactions. When bodily functions are not of interest and the emotional side is, sympathetic nervous system is your choice.

The sweat glands are exclusively innervated by the sympathetic nervous system. This makes EDA an ideal measure for sympathetic activation.2 Electrodermal activity correlates to general emotional intensity, negative emotion, concern, and anxiety. 1, 3 These emotions cause almost similar electrodermal responses, which makes them very hard to differentiate. However, Moodmetric will tell you if certain parts of your day have brought up emotions or not. Inversely, Moodmetric tells you weather you are calm or not. This is particularly useful during your mindfulness, meditation and other calming exercises.

Mobile EDA devices have been used by scientists for some time2, 4, and now we bring this technology within everyone´s reach.

Signal accuracy

The signal accuracy has been proven in a study of 24 people by the Finnish Institute of Occupational Health by J. Torniainen et al.. The accuracy against a laboratory grade reference was found to be 83 %. They conclude:

“Clearly the ring sensor can be used to measure a valid EDA signal as indicated by the similarity of both event-related responses and the calculated features. The accuracy of the Moodmetric EDA Ring is adequate for psychological and physiological research when weighted against the advantage of conducting ecologically valid experiments outside laboratory conditions.”

The results have been accepted for publication in the 2015 conference of the IEEE Engineering in Medicine and Biology Society (EMBC 2015, August 25-29).

Our measurement has been proven to be accurate also by University of Tampere, Finland. The correlation with the reference equipment Nexus-10-MK II was good. Comparison details in charts below.

image1 image2 image3 image4

1 Mendes, W.B. (2009). Assessing the autonomic nervous system. In: Harmon-Jones   E. ja Beer J.S. Methods in social neuroscience. New York: Guilford Press. p. 118-147.

2 Setz C., Arnrich B., Schumm J. and La R. (2010) Discriminating Stress From Cognitive Load Using a Wearable EDA Device. IEEE Trans. Inf. Technol. Biomed. 14(2). p. 410-417.

3 Nikula R. (1991) Psychological correlates of nonspecific skin conductance responses. Psychophysiology. 28(1). p.86-90.

4 Poh M.Z, Swenson N.C. and Picard R.W. (2010) A Wearable Sensor for Unobtrusive, Long-Term Assessment of Electrodermal Activity. IEEE Trans. Biomed. Eng. 57(4). p. 1243-1252.


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