Small Devices, Big Data

Sensor technology is gradually transforming public health and is becoming of increasing interest in medical and clinical applications.

Translating big data collected from sensors into useful healthcare insights is of particular relevance. For instance, data from activity sensors and physiological sensors can be correlated with health information to identify health risks and problems. GRaCE-AGE, a project within the European Institute of Innovation and Technology (EIT) Health, is doing just that – employing sensor technology for the purpose of understanding, supporting and promoting healthy, active ageing.

GRaCE-AGE is a web-based mental-health support system utilizing medically validated sensors in monitoring and managing mental health risk and wellbeing in older adults. GRaCE-AGE is a derived from GRaCE (Galatean Risk and Care Environment), the enhanced and extended version based on Galatean Risk and Safety Tool (GRiST), which is a computer program containing mental health risk and safety expertise that has been developed with clinicians and patients over a period of fifteen years.

Data collected from one or more sensors is analysed and interpreted in the light of questions used by assessors for evaluating safety and wellbeing, which then simulates answers given by assessors. Table 1 shows a list of GRiST parameters and the sensor data output for such applications.

Using collated data input from older adults and various sensors, its inbuilt expertise will highlight any health or safety problems, compute a next course of action, and connect them to their care network to elicit help if necessary. This system aims to engage older adults while facilitating communication with people in their care network, clinical services and expert advice so that they are able to live safely and with a peace of mind.

With the rapid rise in the proportion of older people in society, there is an increasing concern to address the specific needs of this population. Maintaining mental, social, and physical health are as important in old age as in early years, and are important in prolonging independence and quality of life.


To find out more about sensor technology and its applications, contact us!

To find out more about GRaCE-AGE, click here.

Do pedometers do more harm than good?

Speaking at the annual meeting of the American Association for the Advancement of Science (AAAS) in Boston, Dr Greg Hager, professor of computer science at Johns Hopkins University, warned that obsessing over achieving the basic philosophy of 10,000 steps daily may lead people to chase over-ambitious goals and, as a result, do more harm than good.

Why 10,000 steps?

The leading expert pointed out that the target appears to be a relatively arbitrary figure. “Turns out in 1960 in Japan they figured out that the average Japanese man, when he walked 10,000 steps a day, burned something like 3,000 calories and that is what they thought the average person should consume. So they picked 10,000 steps as a number.”

Are pedometers recommended for monitoring physical activity?

Physical activity monitors or trackers, such as pedometers, have gained increasing popularity. When used appropriately, they serve a useful purpose by providing objective measures in activity and provide constant encouragement for people to move more. Pedometers can be a useful tool to create general awareness of activity levels by counting the number of steps taken. However, some users may become fixated on the “10,000-step rule”.

Should I be counting steps?

Rather than being fixated on reaching 10,000 steps a day using a pedometer, it can be used to track the average daily step count, then applied to setting appropriate goals. For a generally healthy individual looking to increase activity in daily routine, gradually increasing the number of steps may be a good way to start. While 10,000 steps per day may have a positive effect on health, it is important to note that the target is not based on science-based evidence. In addition, achieving 10,000 steps may not be feasible for everyone.

Are pedometers recommended for monitoring physical activity?

Relying solely on pedometers in measuring physical activity is unreliable. For one thing, it does not provide important measurement parameters such as duration and intensity. This highlights an important medical risk associated to the application of pedometers and consumer activity trackers in clinical applications.

Activity monitoring for research or clinical applications needs to be precise and validated. For this purpose, accelerometer-based activity monitors, such as the MOX, is used extensively. The MOX has been used to investigate the correlation of physical activity or sedentary behaviour to disease outcomes, as well as to monitor older adults and individuals with chronic conditions in the home and community settings. By customising accelerometer-based algorithms that accurately classify physical activity levels and/or posture such as sitting or lying for specific populations or individuals, reliable and valuable insights into real-world physical activity or movements can be obtained. Combined with activity goal settings, the activity monitor can be used to support translational care interventions. Furthermore, this information enables medical professionals to monitor and support their patients and provide more precise medical advice.

To find out more about the MOX Research system, click here.

Do you have ideas for physical activity monitoring? Feel free to contact us and discuss your ideas!

Quantifying free-living sedentary behaviour using activity monitors

Assessing physical activity

Quantifying physical activity, or lack thereof, have been used to analyse sedentary behaviour in order to understand physical activity and disease outcomes, as well as define the effectiveness of intervention strategies. Physical activity has previously been assessed by means of self-reported measures such as questionnaires and interviews, especially in larger population studies. However, such self-reported measures can report bias in the study. With advancement in technology, wearable activity monitors are increasingly being used to objectively quantify free-living sedentary behaviour. Furthermore, they are generally small, lightweight, portable, non-invasive and unobtrusive.

The study

A recent large population study (2,497 individuals) published in the journal Diabetologia on 2 February 2016 (1) was one of such studies undertaken to measure free-living sedentary behaviour using wearable activity monitors. The study, led by first author Julianne van der Berg and senior author Annemarie Koster from Maastricht University, looked at the amount and patterns of sedentary (sitting or reclining) behaviour in relation to type 2 diabetes and the metabolic syndrome. It was performed within The Maastricht Study, an extensive phenotyping study of adults that focuses on the etiology of type 2 diabetes and its complications and comorbidities.


The study participants with Type 2 Diabetes spent less time stepping and had less moderate intensity activity but the most significant risk factor is the increased time spent sedentary (sitting/lying). It was concluded that an extra hour of sedentary time was associated with a 22% increased risk for type 2 diabetes and 39% increased risk for the metabolic syndrome. These results suggested that sedentary behaviour may play a significant role in the development and prevention of type 2 diabetes.

Fig. 1 Time (hours) spent in primary daily activities according to glucose metabolism status. (Adapted from van der Berg et al., 2016) (1)

Activity monitors

There are activity monitors that have been developed for research purposes and more specifically, for accurately distinguishing sedentary behavior. The Glasgow-based PAL Technologies’ activPAL™ activity monitor was chosen by the researchers in the Maastricht Study. Similarly, the MOX activity monitor has proven high accuracy in determining free-living physical activity behavior and assessing different activity intensities in healthy and chronically ill patients (chronic obstructive pulmonary disease, type 2 diabetes or mitochondrial disease) (2, 3). Furthermore, the MOX activity monitor is waterproof and can be adhered directly to the skin on the thigh 24/7 for 8 days by a patch. Using accurate, reliable and objective activity monitors is an advantage as advances in accelerometry technology have allowed low power consumption, easy setup, and unobtrusive design to provide a promising tool for monitoring free-living physical activities.

Click here to the article by van der Berg et al. published online in the journal Diabetologia, 2016.


  1.  van der Berg JD, Stehouwer CDA, Bosma H, van der Velde JHPM, Willems PJB, Savelberg HHCM, et al. Associations of total amount and patterns of sedentary behaviour with type 2 diabetes and the metabolic syndrome: The Maastricht Study. Diabetologia. 2016;59(4):709-18.
  2. van der Weegen S, Essers H, Spreeuwenberg M, Verwey R, Tange H, de Witte L, et al. Concurrent Validity of the MOX Activity Monitor Compared to the ActiGraph GT3X. Telemedicine and e-Health. 2015;21(4):259-66.
  3. Koene S, Dirks I, van Mierlo E, de Vries PR, Janssen AJWM, Smeitink JAM, et al. Domains of Daily Physical Activity in Children with Mitochondrial Disease: A 3D Accelerometry Approach. Berlin, Heidelberg: Springer Berlin Heidelberg. p. 1-11.

For more information about The Maastricht Study:


For further information about the Maastricht Study, please contact :

Annemarie KosterAnniemarie Koster
Associate Professor

Associate Professor Programme: Inequity, Participation and Globalisation (IPG)
Sociale Geneeskunde, School for Public Health and Prim Care, Fac. Health, Medicine and Life Sciences

Exercise Does Not Negate the Harmful Effects of Inactivity

Exercise is healthy, but an hour per day cannot fully compensate for the negative effects of excessive sitting and inactivity during the rest of the day.

It is generally known that exercise is beneficial for health and in reducing the risk of metabolic diseases such as diabetes and cardiovascular diseases. Unfortunately, many adults do not reach the current physical activity guidelines (150 minutes of moderate to vigorous physical activity per week). Moreover, we sit too much. In the car/bus on the way to work, at work behind our desk and at home in front of the television or computer. Inactivity, especially excessive sitting, is a major implicator of metabolic diseases and has been branded the “new smoking” for its supposed health risks. Whether this statement is true is inconclusive based on current research, but one thing most researchers do agree: too much sitting is unhealthy.

Decreasing sitting time by moving more and fitting physical activity into your day is one way to get started. Other than a bout of exercise a day, an easy alternative is to increase movement in our daily activities, such as housework, gardening, walking or cycling as a mode of commute and taking the stairs. A recently published study by Duvivier et al. (in scientific journal Plos One) suggested that one hour of daily physical exercise cannot fully compensate for the negative effects of inactivity on risk factors for cardiovascular disease (insulin level and plasma lipids) if the rest of the day is spent sitting.

The Study

In this study, eighteen healthy young subjects, age 21±2 year old of normal BMI followed one of three randomly assigned physical activity regimes for four days. In the sitting regime, participants were instructed to sit 14 hr/day. In the exercise regime, participants were instructed to sit 13 hr/day and to substitute 1 hr of sitting with 1 hr of vigorous supervised bicycling. Lastly, participants in the minimal intensity physical activity regime were instructed to substitute 6 hrs sitting with 4 hr walking and 2 hr standing. All regimes were instructed to walk 1 hr/day, stand 1 hr/day and spend 8 hr/day sleeping or supine. The exercise and minimal intensity physical activity regime had the same daily energy expenditure. During the four days of regime, physical activity monitors were continuously worn (24 hours a day) by the participants.



Figure 1. Time spent on different activities per regime.
Graphical overview of the three regimes followed by the participants and time spent in different activity categories (sleeping, sitting, standing, cycling and activity (walking).


Results of the study showed that reducing inactivity by increasing the time spent walking/standing is more effective in lowering blood cholesterol and lipid levels, when energy expenditure is kept constant. Moving more everyday and reducing prolonged sitting time is much more effective than a bout of one hour intensive cycling exercise. It also demonstrated that the negative effects of extensive sitting on our health cannot be compensated by an hour of exercise per day. Therefore apart from including exercise in our lifestyle, health advice should also focus on decreasing sedentary time and moving more.

One of the strategies to keep track of daily movements is the use of an activity tracker. Physical activity trackers have gained popularity to assist individuals in monitoring their level of activity and reaching their daily activity goals.

Duvivier BMFM, Schaper NC, Bremers MA, van Crombrugge G, Menheere PPCA, Kars M, et al. (2013) Minimal Intensity Physical Activity (Standing and Walking) of Longer Duration Improves Insulin Action and Plasma Lipids More than Shorter Periods of Moderate to Vigorous Exercise (Cycling) in Sedentary Subjects When Energy Expenditure Is Comparable. PLoS ONE 8(2): e55542.

Download the article here.

For more information about this study, please contact:

Bernard Duvivier

Bernard Duvivier, MD

Department of Internal Medicine
Department of Human Movement Sciences
Maastricht University Medical Centre
Maastricht, The Netherlands

Measurement and promotion of physical activity

Sufficient physical activity is essential for cardio-metabolic health and quality of life. However, inactivity and sedentary behavior such as sitting, which is associated to an array of health risks, is prevalent in our current way of living. Promotion of physical activity is therefore crucial.

Research into the promotion of physical activity has revealed that altering one’s lifestyle or losing excess weight can be challenging and is often accompanied by barriers. Practice nurses, physiotherapists and dieticians can provide support in making lifestyle changes. One of the combined strategies aimed at increasing physical activity is adding group sessions, however it is uncertain whether it positively enhances the effectiveness of lifestyle interventions. In order to define the effectiveness of intervention strategies, accurate measurement of physical activity is paramount for correct interpretation of study results. Several instruments exist to estimate physical activity levels, such as questionnaires and body-fixed activity monitors. When deciding which activity monitor to use in research and daily practice, popularity of a device is not necessarily the best option as it may not imply usability. Moreover, whether activity monitors can truly reflect the level of physical activity and sedentary behavior is still a subject of discussion.

The effectiveness of a multidisciplinary lifestyle program in increasing physical activity levels was evaluated in a study by Brenda Berendsen as part of her PhD thesis. The intervention was offered to 30 family practices across the Netherlands to more than 400 people by a team of nurses, physiotherapists and dieticians. In her PhD thesis defense, Brenda Berendsen presented distinct differences between activity monitors that were used in this study, these included the accuracy and ease of use. Three activity monitors were investigated: the CAM (forerunner of MOX, Maastricht Instruments), ActiGraphGT3X and ActivPal3. Results revealed that the differences in sitting, standing and time in motion was best represented by two monitors (CAM and ActivPAL3) that were worn on the thigh. Feedback from questionnaires on the CAM, ActiGraphGT3X and ActivPAL3 demonstrated that ActiGraphGT3X (46 x 33 x 15 mm; 19 g), worn around the waist, was very comfortable to wear. Participants found the CAM, which was the largest monitor (63 x 45 x 18 mm; 100 g), the most physically apparent while performing daily activities. With that consideration, Maastricht Instruments developed the MOX, a smaller monitor that is more compact and less obtrusive than the CAM.

Furthermore, Brenda Berendsen's dissertation described the process and effectiveness of an intervention to encourage exercise and healthy diet in overweight people. In addition, the study showed that an intervention of a multidisciplinary lifestyle program was effective in increasing physical activity levels. However, an adequate amount of delivered therapy hours was required to benefit from the physical activity program.


brenda-berendsenBrenda Berendsen, PhD
Open University Heerlen, Department of Psychology and Educational Sciences

Brenda Berendsen defended her thesis "Measurement and promotion of physical activity: Evaluation of activity monitors and a multidisciplinary lifestyle intervention in primary care" on June 24, 2016 at 14.00 at the University of Maastricht. Download the article here.