Due to social and economic changes and technological progress, humans no longer follow the natural light/dark cycle, but live in a 24-hour society. Daytime is spent in indoor settings, where light levels are a fraction of those outdoors. The darkness during the night is impacted by the use of artificial light. Whereas the connection between light exposure and human circadian entrainment is well established, the research community was missing two key items for a long time:

• an agreement on what metrics to use
• a suitable measuring device

The first gap was closed with the publication of CIE S 026:2018 – «CIE System for Metrology of Optical Radiation for ipRGC-Influenced Responses to Light»; the second gap is being addressed by the light-dosimeter.

Now we can answer your question: What about my light-history ?

The light-dosimeter (lido) is a mobile measurement device to investigate the non-visual responses to light. Attached to a pair of glasses, it records a person’s light exposure in the near-corneal plane, which is viewed as the best available proxy to retinal irradiation by most researchers. Thanks to a bespoke mounting it can be taken off during a recording, if required. The custom-made software «Lido Studio» converts the measurements into the metrics standardised in CIE S 026:2018. Data can be analysed directly in Lido Studio or exported as a PDF report or a comma-separated values (CSV) file for further in-depth time-series analyses. The light-dosimeters were tested by the Swiss Federal Institute of Metrology (METAS). The reports are available upon request.

The light-dosimeters’ key specifications are:

• Spectral range: 380 nm – 780 nm
• Intensity range: from 5 lx – 100k+ lx
• Measurement interval: 10 sec
• Battery life: 7 days
• Interface: Micro-USB

After the Velux Stiftung approved the funding for the project «Light exposure and health – light-dosimeter for the longterm recording and examination of biologically effective radiation and its effect on humans» (Project No. 1134), an interdisciplinary team from the Lucerne School of Engineering and Architecture, combining knowledge in light and lighting, electronics, product design, information technology and project management, started with the development of the light-dosimeter in early 2018.

People who contributed to the project from the Lucerne School of Engineering and Architecture:

• Prof. Björn Schrader, Institute of Building Technology and Energy (IGE)
• Prof. Othmar Schälli, Institute of Electrical Engineering (IET)
• Dr. Giselher Wichmann, Institute of Electrical Engineering (IET)
• Prof. Erich Styger, Institute of Electrical Engineering (IET)
• Christian Di Battista, Institute of Electrical Engineering (IET)
• Janine Stampfli, Institute of Building Technology and Energy (IGE)
• Reto Häfliger, Institute of Building Technology and Energy (IGE)
• Christoph Zumbühl, Institute of Electrical Engineering (IET)
• Martin Friedli, Institute of Electrical Engineering (IET)
• Said Ahsaine, Institute of Building Technology and Energy (IGE)
• Stefan Ineichen, Institute of Building Technology and Energy (IGE)
• Diego Rohner, Institute of Innovation and Technology Management (IIT)
• Silvio Emmenegger, Institute of Electrical Engineering (IET)
• Christian Jost, Institute of Electrical Engineering (IET)
• Stefan Lustenberger, Mechanical Engineering and Energy Technology (IME)
• David Huwyler, Institute of Electrical Engineering (IET)
• Erny Niederberger, Institute of Electrical Engineering (IET)
• Justin Rüssli-Kueh, Institute of Electrical Engineering (IET)

MeLiDos EURAMET
directly involved: University of applied science Luzern

MeLiDos on Zenodo

MeLiDos-Website

 LightLogR 

Presentations:

• Fachsymposium Licht- und Lebensqualität, Weimar, Deutschland, Lichtdosimetrie: Fact or Fiction, O. Stefani (12./13.10.2023)
• Good Light Group meeting #16 , Online: The luminous landscape of light loggers, O. Stefani (26.9.2023)
• LICHT 2023, Salzburg, Austria: lido – Das Light-Dosimeter zur Erforschung der nicht-visuellen Wirkungen von Licht , B. Schrader (26./29.3.2023)
• DLA Summer School, Lausanne, Switzerland: The Light-Dosimeter – a novel, portable device to record an individual’s light exposure, B. Schrader (15.8.2022)
• Tageslicht-Symposium 2022, Basel, Switzerland: Wie viel Licht erhalten Sie pro Tag?, J. Stampfli (15.6.2021)
• Optica Webinar, Online: Measuring Light, Color, Spectrum and Personalized Light Exposure Using Wearable Light Sensors (11.2.2022)
• Daylight Academy Annual Conference 2021, Online: Light-Dosimeter, J. Stampfli (2.12.2021)
• CIE Midterm Conference 2021, Online: The Light-Dosimeter – A New Device to Help Advance Research on the Non-visual Responses to Light, J. Stampfli (27.9.2021)
• Tageslicht-Symposium 2021, Online: Licht-Dosimeter (17.6.2021)
• Swiss Lighting Forum, Basel, Switzerland: Human Centric Lighting – Hohe Erwartungen wecken reicht nicht aus, B. Schrader (30.1.2020)
• BioWi, Weimar, Germany: Licht-Dosimeter – Aufzeichnung einer ‘Light History’ von Probanden, B. Schrader (12.11.2019)
• EUROSHNET, Dresden, Germany: Light dosimeter – recording an individual’s light history, R. Häfliger (12.6.2019)
• LICHT2018, Davos, Switzerland: Light-Dosimeter 2.0 for Research, B. Schrader (11.9.2018)
• Light & Building, Frankfurt, Germany: HCL-Light-Dosimeter 2.0 – Zur Erfassung der zeitlichen Strahlenexposition von Probanden, B. Schrader (22.3.2018)

Lucerne School of Engineering and Architecture
Technikumstrasse 21
6048 Horw
Switzerland