Do you study stress, customer experience, attention or decision making?

The Moodmetric measurement gives accurate and real time data on cognitive and emotional load of an individual. Use cases below give a snapshot on what kind of research it can be applied to. These are just a handful of examples. Electrodermal activity is a signal with great and for most unused potential in field research.


Positive stress is a good thing and when in control, it takes us forward. Chronic stress reduces productivity, creativity and job satisfaction and it is a risk for physical and psychological health. It is not easy to catch signals early and stress might not be detected before it has reached harmful levels.

Questionnaires are subjective and bound to a certain moment. Preventive stress management needs continuous and long term measurement. The Moodmetric ring is intended for weeks and months of use. The mobile app offers a real time view which enables insights that can be actioned immediately.

Even though the Moodmetric measurement is primarily intended for use at occupational health, the real time measurement enables several kinds of research. Below are some example use cases to give a picture of it´s possibilities:

Customer experience

A customer is testing a new shopping center virtually. The center is equipped with innovative implementations, including parking, navigating inside the center, paying in the shops (only mobile payment) etc. The pilot customers´ opinion have a major significance on the final drawings and the pilot is heavily studied. The Moodmetric measurement shows instantly and in real time the pain points – when the experience is getting from smooth to troublesome. The Moodmetric levels increase in seconds when the customer is perplexed.

A much simpler example would be e.g. driving through a car washing lane. How many of the customers actually get terrified inside, with not way of getting out in the middle? Could this be eased out somehow?

The Moodmetric measurement can be used to tracking stress levels in any environment, inside or out in the woods. It suits to observing a person in different situations, like choosing clothes. Which print makes the person react?


Mobile and desktop games can be extremely agitating. Chasing, fighting, racing and performing dangerous tasks is enervating. The sympathetic nervous system of the player is active, as the body does not understand that the threat is just an illusion created by the game developer.

A game can also be soothing, like puzzles. Focus is needed but vigilance not.

What kind of a game is yours and what is the target audience? What if you could design games that really calm down the sympathetic nervous system – a game that you could wholeheartedly recommend e.g. for kids with concentration difficulties?

Pay attention!

We make better decisions, our movements are correct and precise, and we make better analysis when we pay attention. Really pay attention by not letting noises, lights, phone, emails or the smell of lunch distract us.

The Moodmetric index of 1 to 100 tells our arousal level. When focused, the level is below 30, in most cases below 20. Full focus on the task at hand might show a steady level of 12 with almost a straight electrodermal activity curve on the Moodmetric mobile app. The person is far from being sleepy (although in the evening at the sofa the numbers might be exactly the same), but fully focused.

This does not necessarily need an isolated environment. Most people can find their way to reach focus no matter the surroundings. But as it is not easy, many companies design spaces and areas inside their offices that enhance concentration.


What kind of training methods provide the best results? The Moodmetric measurement makes it possible to better understand what level of focus the athlete reaches. Interventions such as mental exercises can tested and found out the ones with the best results for improving concentration. The measurement also provides insights as to when recovery from practice is sufficient. The app diary helps to analyse which activities should be toned down or avoided in order to benefit optimally from training.


Interested to know more about the Moodmetric measurement and why the Moodmetric ring is especially well suited to measure electrodermal activity?

Read our recently published articles starting with:

PART 1: Fight or flight response

Applications in research and ongoing projects:


Or contact us directly:
Niina Venho / CEO
niina. [email protected]

PART 4: The Moodmetric ring stress measurement and understanding the data

This article series tell about stress and ways to measure it. Parts 1 and 2 describe the fight or flight reaction and how the body reacts to chronic stress. Methods for long term monitoring are presented in part 3. In this article we explain the Moodmetric ring measurement and how to interpret the data.

The Moodmetric smart ring measures electrodermal activity. It detects skin conductance with the band of the ring that works as electrodes. The band consists of two silver coated steel rings, and an insulator band in between them. 

Electrodes need to get a good contact with an area on skin where the eccrine sweat gland density is high. This varies from 400/cm2 on the palm to about 80/cm2 on the upper arm. A ring form for the Moodmetric sensor has been chosen to reach the best possible accuracy. The measurement point is on the palm side of the finger and at best the signal is unbroken.

The ring measures continuously and stores the data inside the ‘stone’. The mobile app does not need to be on, nor the phone near the ring. When the app is opened and the calendar icon chosen, the ring sends the data to the app via bluetooth connection. The measurement and data storing to the ring continue immediately. The real-time signal can be followed any time with the app.

Research by the Finnish Institute of Occupational health (2015) shows that the signal of the Moodmetric ring is comparable to that of a laboratory device. The ring is applicable for field studies.

The Moodmetric signal

The Moodmetric signal is the violet curve on the mobile app that can be observed real-time. It is the raw measurement signal but auto scaled in order to have the whole amplitude visible even during strong reactions.

The curve enables analysis of single reactions. Even a thought can cause a peak: excitement, idea, awe – each reaction forms a peak within a 1-2 second physiological delay.

Interpreting the raw signal requires expertise in the measurement method and understanding the possible sources of error.

The Moodmetric index

The electrodermal activity (EDA) raw signal is difficult to interpret and prone to errors. Strong reactions can easily be spotted on the curve,  but mathematical methods are needed for further analysis.

The Moodmetric index or the Moodmetric level has been developed to solve challenges related to EDA measurement. The algorithms count an index from 1 to 100 so that 1 is the lowest the person can reach. This is possible e.g. in deep sleep. 100 is the maximum arousal, strongest possible reaction of the person. Finding the min and max takes about 12 hours, which is the calibration period. The ring can be re-calibrated e.g. when changing from one user to another.

The Moodmetric index/level tells the activity level of the person at a certain moment, looking at a few minutes´ time window. The level does not indicate single reactions but changes fast if the arousal level of the person increases or decreases rapidly. E.g. increasing is first seen in growing amplitude and raising trend of the Moodmetric curve, then in higher Moodmetric level.

It is easy to get to 100. What is more interesting is to make rehearsals that aim to calm the mind, to get the index as low as possible.

In counting the Moodmetric index, the algorithms minimize the effect of finger’s movement and the skin normal moisture level on the measurement. The index is comparable between users. If two persons are at a same situation it is possible to observe which one is calmer.

There is no momentary optimal value

It is normal that the Moodmetric level fluctuates between 1 and 100 during the day. No momentary value is good or bad.

Important is also to know, that the Moodmetric measurement does not tell whether a reaction is positive or negative. The Moodmetric ring is not an emotion detector.

The fluctuation of stress levels is individual

There are people who react fast and strong, while others respond more calmly. For instance creative people are often very prone to stimulus and they get a lot of new ideas. This can be seen in high Moodmetric levels as well as big fluctuation. A person doing work that requires deep and long concentration might have low Moodmetric levels throughout the working day.

The levels can be high due to excitement and energy, or low due to good focus. All this is positive. The levels might also be high due to pressure and lack of control at work. Low figures in turn can tell of boredom or even depression. The measurement data always needs the ring wearer´s own perception of the situation. No one else can tell whether the 100 on the mobile app tells of excitement or irritation.

A good team is heterogeneous also by the way they react

At workplace it is good to have people with different ways to react. A team with individuals that all have a very mild or a very strong natural way to react, probably is not as productive as a more heterogeneous team.

The Moodmetric measurement helps to understand individuals and personal ways to react. This is important from wellbeing point of view. We should rather challenge ourselves keeping in mind our own physiology and environment, than compare to others.

The Moodmetric daily average level is the most important

The Moodmetric smart ring measures the sympathetic nervous system reactions on a scale from 1 to 100. Counting presumes balance. When the daily average value is around 50, there is enough recovery in correlation to load. The Moodmetric ring users notice the same: the daily average is normally 45 to 55 depending on how well daily load is compensated by rest and sleep.

Levels and fluctuation during the day can be very different between two persons. Both might still feel well and with plenty of energy. If high daily figures are combined with very restful sleep, can the daily average level be the same as with a person with much lower numbers during daytime. 

Below the different persons’ consecutive day and night views, where the daily average for both arrived at 46. In this example both reached good, quite a low average, but with very different daily levels:

The daily average of the Moodmetric index is the more informative, the more the person uses the ring. It is easier to analyse own balance of load and recovery when the ring is worn also during the night.

Feedback from the Moodmetric ring users tells that own perception is in line with the measurement. If the daily average is around 50, the situation and energy levels are normal. Values over 50 for a long time go hand in hand with the feeling of overload and weakened wellbeing. Very low daily figures might indicate depression.

The Moodmetric measurement helps the user to gain balance between load and recovery. The sources of stress and ways to recover are individual. For this reason the measurement data always needs own evaluation. Categorizing and analyzing own life e.g. with the help of the Moodmetric app Diary feature is a way to more balanced life.

The complete set of 5 articles:

  1. Part 1: Fight or flight response
  2. Part 2: Chronic stress – The brain concludes that we are continuously in danger
  3. Part 3: Tools for long term and continuous stress measurement
  4. Part 4: The Moodmetric ring stress measurement and understanding the data
  5. Part 5: The Moodmetric measurement in preventive occupational health 

PART 3: Tools for long term and continuous stress measurement

Stress can be measured in several ways in clinical setting. The measurements done in laboratory  give versatile and accurate information. But as we do not live in a laboratory, they can not interpret the changes in our daily lives. Researchers and individuals need tools for long term and continuous stress measurement.

For decades there has been reliable methods available to measure stress in laboratory setting. These methods  include heart and heart rate variability measurement performed with several accurate sensors. Other heart related tests are blood flow measurements with long term registration of electrocardiography and blood pressure. Additionally there are tests on the autonomic nervous system and biochemical tests. The biochemical tests include hormonal and immunological definitions of blood, saliva and urine.

While servicing hospitals and research laboratories, these methods can not give a full picture on person´s stress level. Chronic stress develops over a long period of time and recovery can take weeks and months. User friendly methods that fit to daily life are needed to measure stress in long term.

Non-intrusive wearable devices are the solution for long term meausurements

People are not willing to make huge compromises when it comes to health and wellbeing interventions. Activity trackers and other wellbeing devices have brought everyone the possibility to understand own physiology. Some of these equipment also draw conclusions on the stress level of the user.

Physiological measurement methods to follow stress levels for weeks or months are not yet available for clinical use. At the moment continuous and long term stress measurement can be done by measuring heart rate variability or electrodermal activity.

Heart rate variability (HRV)

A healthy heart is not a metronome. Heart rate variability means the variation between consecutive heart beats. At rest the variation can be from a few tens upto a hundred millisecons.

Why the heart rate varies

Heart rate variability is a way for our body to regulate optimal blood flow to the brain. The more variation there is between the beats, the bigger the activity of the parasympathetic system. This means that the recovery functions of the body work well.

When action is needed the rest-and-digest functions of the body are shut off. Heart rate variability gets smaller for instance during the fight or flight response that activates the sympathetic nervous system. The heart pounds with regular beats. This is because in a fight the purpose is to stay alive and not fine tune bodily functions.

Factors affecting HRV

The heart rate variability is affected mostly by age, gender and pulse. The higher the age and the resting heart rate, the smaller the variation. Additional factors are physical and mental stress, smoking, alcohol and coffee, overweight, blood pressure and glucose level, infectious agents and depression. Also the inherited genes affect the heart rate variability significantly. Individual variation is large and therefore there are no clear set limits. During measurements it is important to pay attention to rest and physical load. When the heart rate goes up due to physical strain, the heart rate variability decreases.

Counting heart rate variability and accuracy of measurement

Heart rate variability as a phenomenon is known since 1960’s and applied in health care for a long time. The most accurate way for measurement is the electrocardiography (ECG or EKG). For wellbeing uses there are several devices available, out of which most accurate are those measuring from chest. Wrist and finger measurements suffer in accuracy especially with high heart rates due to movement of the measured spot.

Heart rate variability is measured by calculating the time interval between heartbeats. This is normally done by looking at the R spikes on an electrocardiogram, the R-R interval. Mathematical methods are needed in the analysis of the heart rate variability. With advanced algorithms it is possible make deductions about a person´s physical and mental load.

Heart rate variability is high at rest, when the person is young and healthy and with a good physical condition. Low HRV might indicate stress for a healthy adult.

Electrodermal activity (EDA)

also: galvanic skin response (GSR), skin conductance response (SCR)

A physiological phenomenon known since over hundred years is electrodermal activity. Psychological factors affecting the conductance of skin was found almost simultaneously by a French neuroscientist Féré (1888) and a Russian physiologist Tarchanoff (1889). The first observations had been done already over ten years prior by a French threrapist Vigouroux. Out of several naming conventions for the phenomenon  the electrodermal activity (EDA) prevailed.

Electrodermal activity from physiological point of view

The skin  becomes a better conductor of electricity when the eccrine sweat glands process sweat to skin surface. Eccrine glands are innervated by the sympathetic nervous system and are part of the fight or flight response system. This makes electrodermal activity (EDA) important from stress measurement point of view. The major reason for it’s importance lies in the fact that EDA is solely mediated by the sympathetic branch of the autonomous nervous system, thus being not subjected to parasympathetic influences as most of the other autonomic measures (1).

EDA measurement

There has been equipment available for laboratory level EDA measurement since founding of the phenomenon. Usually the measurement is done from palms or fingers with electrodes that are connected to an amplifier.

An unprocessed EDA signal is very sensitive to movement, so in most test settings the subject is requested to stay still. In the past this has limited the EDA measurement mainly to laboratory.

Lately the wearable technology development has made improvements also to EDA studies. Advanced algorithms and signal processing have made it possible to compensate the movement artifacts, and wearable sensors have been brought to market.

Measuring EDA as a continuous long-term measurement in a non-intrusive way is desirable for many different fields of research and diagnostics (2). Studies in psychology and behavioral sciences benefit when the measurements can be done in normal daily life, outside laboratory. Additional advantage is that wearable technology enable research with moderate equipment cost.

Measurement units, parameters and accuracy

EDA measurement registers the inverse of the electrical resistance ‘ohm’ between two points on the skin – i.e., the conductivity ‘siemens’ of the skin in that location (3). The recorded EDA signal has two components. The slowly varying tonic component of the EDA signal represents the current skin conductance level (SCL). The skin conductance response (SCR) corresponds to sympathetic arousal (1). It is a spike-like component whose amplitude and frequency indicate of the person´s activation level. EDA does not tell whether the person is experiencing something positive or negative. Raise in activation level can be due to any strong emotion such as excitement, joy, fear and anger.

The accuracy of the measurement depends on the equipment used, stability of the environment and the point of measurement. The preferred sites for EDA measurements are located in the palms of the hands and the soles of the feet (4). Age and gender affect EDA somewhat. External temperature and movements of the person have an effect on the measurement signal that needs processing to draw the right conclusions.

EDA measurement can be very accurate also in wearable form. Field studies with these devices are possible already today.

Applications of EDA

Electrodermal activity has a lot of clinical and practical applications, with polygraph one of the most well known. In psychological research the phenomenon has been applied since it was first found. Later the uses have been across many fields e.g. gaming and user experience, marketing research and in top sports.

The next article in this series tells how the Moodmetric ring measures electrodermal activity

(1) Electrodermal Activity (Boucsein, 2012)

(2) Feasibility of an Electrodermal Activity Ring Prototype as a Research Tool (Torniainen, Cowley, Henelius, Lukander, Pakarinen, 2015)

(3) A short review and primer on electrodermal activity in human computer interaction applications (Benjamin Cowley, Jari Torniainen, 2016)

(4) Electrodermal Activity Sensor for Classification of Calm/Distress Condition (Zangróniz et al., 2017)

The complete set of 5 articles:

  1. Part 1: Fight or flight response
  2. Part 2: Chronic stress – The brain concludes that we are continuously in danger
  3. Part 3: Tools for long term and continuous stress measurement
  4. Part 4: The Moodmetric ring stress measurement and understanding the data
  5. Part 5: The Moodmetric measurement in preventive occupational health 

PART 5: The Moodmetric measurement in preventive occupational health

Stress is a good thing, it is our driving force keeping us active and productive. However, excessive amounts of stress can lead to  overload, especially when the stress load is out of our hands. Chronic stress is a state where stress outweighs recovery. The autonomous nervous system is off balance and the body is continuously in alarm mode.

Chronic stress is in connection with several physical and psychological illnesses, and it is often behind burnout. Overload is difficult to recognize because it builds up over a long period of time.  Stress can also still be a taboo, and people seek help too late. According to research, even 60-80% of medical visits are in connection with stress (Nerurkar et al. 2013). Every fourth tells to suffer from work related stress at some point of their working life.

The Moodmetric measurement

The Moodmetric smart ring is one of the first devices to measure long term stress by interpreting the phenomenon of electrodermal activity / skin conductivity. This physiological measurement can accurately tell about fluctuating stress levels in daily life. Electrodermal activity measurement is especially sensitive to detect changes in emotional and cognitive stress. This makes the Moodmetric smart ring a great stress management tool especially for knowledge workers.

The Moodmetric smart ring is easy to use, and the measurement results can be observed real time on a smart phone screen. A minimum suggested measurement period is two weeks, but the measurement can go on for years when needed. In two weeks the user learns the individual sources of stress and recovery, and gains motivation to seek better balance.

The Moodmetric measurement is real-time, informative, accurate and the ring is comfortable to use also in long term.  The mobile app content is visual and the real time view enables immediate actions. This is very important when seeking behavior changes. Findings can be applied to practice right away.

According to customer feedback, the data collected by the Moodmetric smart ring helps to better recognize individual sources of stress and recovery, and motivates to take concrete actions.

Preventive occupational health is seeking to offer new services

The Moodmetricin reseach and development has been strongly guided by our customer feedback. Customer comments and use cases have been collected since 2015. Especially our corporate customers have repeatedly expressed their wish to have the Moodmetric services available at the occupational health. Individuals often look forward to receive professional help to measurement data interpretation, as well as to better understand good stress management practices.

The occupational health has a limited selection of tools to offer the customers that seek help to manage stress overload, or whose health issues are clearly stress related. Most occupational health customers might not need continuous stress measurement in long term, but they wish a measurement to be available as a service when needed and for as long as needed.

Wellbeing technology can motivate individuals to take an active role in enhancing own health. The Moodmetric mission is to prevent health issues and related costs caused by stress on an individual and community level. Preventive stress management is equally interesting to insurance companies in relevant fields.


Nerurkar, A., Bitton, A., Davis, R. B., Phillips, R. S., & Yeh, G. (2013). When physicians counsel about stress: Results of a national study. JAMA internal medicine, 173(1), 76-77.

Koskinen, S., Lundqvist, A., & Ristiluoma, N. (2012). Terveys, toimintakyky ja hyvinvointi Suomessa 2011. The Finnish institute of Health and Wellbeing , Report: 2012_068.

Picture: Pixabay

The complete set of 5 articles:

  1. Part 1: Fight or flight response
  2. Part 2: Chronic stress – The brain concludes that we are continuously in danger
  3. Part 3: Tools for long term and continuous stress measurement
  4. Part 4: The Moodmetric ring stress measurement and understanding the data
  5. Part 5: The Moodmetric measurement in preventive occupational health 

Electrodermal activity measurement shows athletes new information

Different kinds of physiological measurement systems have been used for a long time in top sports. Wearable devices have made exercise tracking easy for everyone.

Heart rate monitoring is the most used measurement in sports. It was developed by an Australian physician Robert Treffene for swim exercising. In Finland hear rate monitor was invented by the Polar Electro founder, professor Seppo Säynäjäkangas in 1975.

Today there is a huge variety of equipment for hear rate monitoring. The most accurate ones still measure from chest, either with a band or with taped sensors. Wrist worn trackers are comfortable to wear and they have largely displaced chest bands especially with non-professional exercisers. The accuracy of wrist worn trackers has been improved in past years, but it suffers especially at high heart rates.

Heart rate, heart rate variability (HRV) and electrodermal activity (EDA)

Analysing heart rate gives a good view of physical strain. With different algorithms it is possible to understands also recovery, sleep and stress.

Heart rate variability (HRV) has been lately brought up especially in measuring non-physical load. There are challenges, as at high heart rates the algorithms struggle to understand what happens: is the person physically at rest, but nervous (e.g. about a soon-to-start exam), or is it now about physical exercise? Here the accelerometers, present in all of the trackers, are of help. These components can detect whether a person is moving or is at rest, and much more about movement directions and pace.

The electrodermal activity (EDA) measurement brings interesting new information to analyse performance of an athlete. This does not tell about heart, but about sympathetic nervous system activation through sweat gland reactions of skin. Skin is the only organ that is purely innervated by the sympathetic nervous system. The EDA measurement is very sensitive to emotional and cognitive stress, and it has been used in psychological research already for over 100 years. Only lately it has become available for consumers.

The Moodmetric smart ring measures electrodermal activity. The ring is comfortable to wear and it is thus well suited for continuous, long term measurement. Only a sufficiently long measurement period gives a full picture on stress, how it is generated and how recovery happens during weeks, months and even years.

Both top sports, and going after personal goals in exercising benefit of stress load related information. It is good to understand what sources of stress or recovery might affect the performance. For instance, cognitive load of a professional athlete might be less than for someone who need to have a day job to finance the sports career. The professional athlete can probably exercise more, as there is more time for recovery. The results and performance are affected by emotional and cognitive load, if there is no time to unwind.

Read more: Moodmetric-measurement in research

Moodmetric will participate SMASH-sports event in Helsinki the 28-29th November, come to meet us and test the smart ring!

Niina Venho
[email protected]
+358 40 710 4087

Moodmetric data analytics tool

The Moodmetric data analytics tool is created to support research and development projects related to EDA (electrodermal activity) measurements.

The tool enables researchers and developers to quickly process and visualize large Moodmetric data sets in uniform manner. It generates both group and individual level reports based on input data from wearable devices. The tool is released as open source for anyone to benefit of the Moodmetric measurement data in various use cases.

Download the Moodmetric data visualization tool instruction here.

For more information, contact
Jari Jussila
[email protected]
+358 40 717 8345

Electrodermal activity measured by the Moodmetric ring

Electrodermal activity

With any sympathetic nervous system activation, skin reacts and becomes a better conductor of electricity. This can result from emotional, cognitive or other psychological origin. The phenomenon is known as electrodermal activity (EDA) and it is widely adopted in psychological research (1). Other commonly used terms for this phenomenon are skin conductance response and galvanic skin response.

EDA is generated by the 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 eccrine sweat gland density (2). You can measure EDA elsewhere as well but the reliability is not as high or as easily achieved.

The unconscious actions of the human body are regulated by the autonomic nervous system. It consists of the sympathetic and parasympathetic part. The parasympathetic part controls the body’s rest-and-digest functions and the sympathetic part controls the fight-or-flight reactions. By examining electrodermal activity we can understand the sympathetic nervous system reactions.

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 cognitive and emotional arousal, and high responses are caused by e.g. stress, enthusiasm, anxiety, joy, anger (1, 3).

Mobile EDA devices have been used by scientists for some time (2, 4). The Moodmetric ring is an unobtrusive option to follow EDA responses real-time and in long term.

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

Link to the article

The Moodmetric measurement accuracy has also been studied at the University of Tampere, Finland in 2014. The correlation with the reference equipment Nexus-10-MK II was good. Comparison details in charts below.

With skin conductance level (SCL) we refer here to raw measured skin conductance without any filtering. The figures below show the comparison of the two devices. 

Further reading in an article by Jari Torniainen and Benjamin Cowley, published in August 2016:

A short review and primer on electrodermal activity in human computer interaction applications


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.



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.