Understanding the accuracy and reliability of sensors for measuring stress.

Once set up, your app simply works; no hiccups, crashes or other bugs- it is very reliable

Maciej Kos

At a Glance

Study-Facts

  • Context: Doctoral Research Study
  • Number of participants: 25
  • Number of days per participants: 10
  • Number of prompst per Day: 10
  • Number of Items: 10

Study

We are planning to monitor stress on an ongoing basis as one component of our health interventions for patients with traumatic brain injury. For this stress monitoring we plan to use a wrist device that monitors heart rate (HR); electrodermal activity (EDA) and physical activity (Basis Peak watch or Microsoft Band2) . To prepare for this new way of real time monitoring, we need to understand the rel iability and accuracy of these sensors and sensing mechanisms. To this end, we will simultaneously record data from each device while subjects change from periods of stress and relaxation in a laboratory setting, and while going about their daily lives for 3-7 days.

Hypotheses:

Our analyses comparing the various devices will provide us with answers to the following
research questions:

• Which wrist device should we use in our long-term monitoring and health
interventions with TBI patients?

o What is the accuracy and reliability of the EDA measures for each device?
Under what conditions of activity, humidity and arm location?
o What is the accuracy and reliability of the HR measures for each device?
Under what conditions of activity?

• Are there important differences between our standard measures of stress?

Study Design:

laboratory Phase Protocol:

First, we will record each participant's age, gender, BMI, skin color, and various psychological measures. Second, we will attach passive electrodes on the chest for ECG and fingers for skin conductivity. The wrist devices will be worn while the participants perform the assigned relaxation and stress-inducing activities.

Data Collected laboratory Phase:

In this stage, we will collect the data from the following sensors:

• Microsoft Band 2- commercially available consumer wrist band measuring heart rate (HR); electrodermal activity (EDA); accelerometry, skin temperature;

• Basis Peak - commercially available consumer wrist band measuring HR, EDA, accelerometry, skin temperature;

• Empatica E4- commercially available research grade wrist band measuring HR, EDA, accelerometry, skin temperature;

• Firstbeat- commercially available consumer product for measuring HR, HR variability (HRV); and stress classification using ECG electrodes on the chest;

• Engineering 1-330-CZ+ - a laboratory system considered gold standard for accurately measuring EDA, HR, HRV, respiration, temperature;