MIDAS S5 Research — Privacy Policy

Effective date: 17 July 2026 · Doctoral research project MIDAS, School of Medicine, Aristotle University of Thessaloniki (AUTh), Greece

1. Who we are

MIDAS S5 (“Σ5”) is an academic research study on the physiological workload of surgeons, conducted as part of a doctoral dissertation at the School of Medicine, Aristotle University of Thessaloniki, under an approved bioethics amendment. The study is operated by the doctoral researcher (contact below). It is not a commercial service and is used only by invited, consenting study participants.

2. What data we collect

With your explicit consent through Google’s authorization screen, the study reads the following read-only data from your Google account (Fitbit device data) via the Google Health API:

• Activity & fitness — daily step counts and resting heart rate;
• Heart rate — heart-rate measurements, including minute/second-level values during pre-declared surgical-case time windows;
• Heart-rate variability — RMSSD values recorded during sleep;
• Sleep — sleep sessions, duration, stages and efficiency;
• Profile — age only, used once to estimate maximum heart rate. We do not store your name, email, photo or contacts from your Google profile.

In addition, the study stores questionnaire answers you submit on study pages and the pseudonymous study code assigned to you at enrolment.

3. How we use the data

The data is used exclusively for scientific research: computing daily physiological measures (e.g. resting heart rate, sleep quality, heart-rate reserve during surgical cases) and analysing them for the doctoral dissertation and resulting academic publications. Published results are aggregated and cannot identify any participant.

4. Limited Use — Google API compliance

MIDAS S5’s use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements. Google user data is used only to provide the research features described above; it is never sold, never used for advertising, and never transferred except as necessary to operate the study, to comply with law, or as part of aggregated, anonymised research results.

5. Storage and security

• Data is stored pseudonymously (study code, not your name) in a research database hosted on Microsoft Azure in the European Union.
• All data transfers use TLS encryption. Access tokens are stored server-side and are never exposed to third parties.
• Access to the database is restricted to the research team.

6. Sharing

We do not sell, rent or share your individual data with third parties. Only aggregated, anonymised results appear in the dissertation and academic publications. Technical service providers (Microsoft Azure, the study’s workflow server) process data solely on our behalf.

7. Retention and your rights

• Data is retained for the duration of the study and the period required for scientific validation of the dissertation, after which identifiable links are destroyed.
• You may withdraw from the study at any time.
• You can revoke the study’s access to your Google data at any time at myaccount.google.com/permissions.
• You may request access to, or deletion of, your stored study data by contacting us; deletion requests are honoured without affecting already-published aggregate results.

8. Contact

Doctoral researcher, project MIDAS — School of Medicine, Aristotle University of Thessaloniki.
Email: gkntakakis@gmail.com

9. Περίληψη στα ελληνικά