Last month cosinuss° had the pleasure to welcome Märta Sund Levander, Specialist Nurse, RTN, Ph.D., senior associate professor, in Munich. At Linköping University in Sweden Märta is a specialist nurse, a long-standing expert in the field of core body temperature measurements and one of the founders of OxyTemp Sweden.

The aim of her two-day visit was to concretize the jointly planned study in a home-care affiliated hospital unit in Sweden. In addition, the cosinuss° team received exciting insights into Märta’s findings from her previous research work and investigations in the course of a lecture.

OxyTemp: Individual normal values of core body temperature and oxygen saturation

Core body temperature is considered one of the most important parameters for assessing a person’s state of health. However, the previously valid limit value for fever of over 38.0 °C is based on old studies from the 19th century. These have been overtaken by many experts on the basis of the latest studies. Thus, every person has his or her individual temperature range in which he or she feels well and is healthy. This range depends on many different factors, such as age, gender and chronic diseases.

Märtha and her research colleague Ewa Grodzinsky, BLS, PhD and associate professor, and Ingela Hagman, reg. nurse in advance home affiliated care, therefore set the goal with OxyTemp of determining the respective normal ranges of core body temperature and oxygen saturation in healthy and frail individuals. They have just performed a study with measurements of body temperature and oxygen saturation, on five consecutive days when the individual was in habitual condition, i. e , taking into account chronic diseases, daily medication and deviation from current reference values at group level. The sample consisted of 70 healthy individuals between 27 and 80 years of age and 52 frail seniors between 60 and 100 years of age. In particular, the results clarify that what are low or high values for both body temperature and oxygen saturation differ significantly between individuals. The study also found that frail elderly more often manifest lower values in oxygen saturation compared to healthy subjects.

To validate using individual normal to detect deteriorated health status, the next step is a study in collaboration with cosinuss°. The study is expected to start in the fall of 2023 and will be conducted in a Swedish home-care affiliated hospital unit. In addition to morning core body temperature and oxygen saturation (SpO2), which will be measured with the cosinuss° c-med alpha in-ear sensor, both in habitual and deteriorated condition.

Assessment and interpretation of body temperature – Time for a change

In Märta’s one-hour lecture followed by a workshop, the cosinuss° team not only gained an interesting insight into the history of temperature measurement and technological developments, but also exciting results from current research. Märta has built up a great deal of expertise based on her practical experience as well as academic career. She shares her enormous knowledge with enthusiasm. She is passionate about establishing a new approach to interpreting core body temperature, based on the “individual normal value”. In doing so, she sees the ear as the ideal measurement site to capture core body temperature. Due to its proximity to the hypothalamus, the control center of our temperature regulation in the brain, the ear canal offers an ideal and easy to reach access for the measurement with an in-ear sensor.

“I am thrilled with the extent to which Märta shares, confirms, and herself disseminates our ideas on the subject of measuring core body temperature.”

Greta Kreuzer, CEO

cosinuss° is looking forward to working with Märta and her colleagues and is excited about the results of the study.

Interview with Märta Sund Levander

During her stay at our office we talked with Märta Sund Levander about new approaches in measuring body temperature.

More information about Märta and the other initiators of OxyTemp Sweden

Märta Sund Levander, Specialist Nurse, RTN, Ph.D., Senior Associated Professor, is a senior research scientist and university lecturer at the Medical Faculty Linköping University in Sweden. She teaches nursing students at the undergraduate, specialist, and advanced levels. She has several years of clinical and research experience as a specialized nurse, especially in neurosurgical care, elderly care, infection control, as well as research and development. Her research area is assessment and evaluation of health conditions, with focus on interpretation of vital parameters based on the individual normal. She has a special focus on body core temperature and oxygen saturation and its clinical implications. She also focuses on signs and symptoms of infection in critically ill and frail elderly as well as fever in children. In 2004, she published her doctoral thesis in the subject of clinical physiology, especially nursing science. Märta is the Swedish expert in the ISO group for clinical thermometers for more than ten years.

Märta Sund Levander
Specialist Nurse, PhD, Senior Associate professor,
Medical faculty
Linköping University Sweden

Ewa Grodzinsky, Reg. BLS
PhD, Associate Professor
Medical faculty
Linköping University, Sweden

Ingela Hagman
Specialist Nurse

Leif Köldahl
Reg Nurse Civil engineer


  • Melanie Schade

    M.A. Kommunikationswissenschaft und Online-Marketing-Expertin mit Schwerpunkt auf Gesundheits- und Wissenschaftskommunikation. // M.A. Communication Studies and online marketing expert with a focus on health and science communication.