Paul Maas

Paul Maas

Master's Thesis

Ubiquitous Investigation of Overall State of Health Using a Smart Toothbrush in Palliative Care

Michael Nissen (M.Sc.), Matthias Zürl (M.Sc.), Dr.-Ing. Heike Leutheuser, Prof. Dr. Björn Eskofier, Dr. med. Tobias Steigleder

06 / 2022 – 12 / 2022


A major problem in modern palliative medicine is the lack of objective and continuous assessment of the health status of patients. This status can be classified by measurement tools such as the Karnofsky index or ECOG (Eastern Cooperative Oncology Group) score [1]. The suitability of patients for certain therapies is influenced by this measurement [2]. The score of a patient within these scales is largely determined by the ability to perform so-called activities of daily living (ADL) [3]. At the moment, physicians largely rely on questionnaires to assess performance of those ADL. However, this bears the risk that the examination is not representative, as it is collected at a single moment and the patient’s statement may be influenced by the presence of the doctor, and only reflects one point in time. In order to be able to get a more accurate and detailed overview of the current state of health, a passive and continuous assessment of these conditions would be beneficial [4].

A previous InnoLab project chose a novel ubiquitous approach to measure some of these acitivities. One of the selected activities was toothbrushing, which was assessed with a “smart” toothbrush. The device incorporates low power microcontrollers and sensors (accelerometer/gyrometer). Thus, the device passively records toothbrushing behaviour.

The aim of this thesis is to continue development of the aforementioned toothbrush, the identification of promising (movement) features for future overall state of health analysis, and the conduction of a longitudinal observational analysis with healthy participants using the device. The underlying research questions are i) whether it is possible to identify generalizable features in IMU toothbrushing data from healthy participants and ii) whether these hold potential to distinguish between healthy participants and patients with reduced overall state of health in subsequent works.

[1] M. M. Oken, R. H. Creech, D. C. Tormey, J. Horton, T. E. Davis, E. T. McFadden, and P. P. Carbone. Toxicity and response criteria of the Eastern Cooperative Oncology Group. American Journal of clinical Oncology, 5(6):649-655, December 1982.
[2] Michael A. Dunn, Deborah A. Josbeno, and Amy R. Schmotzer. The gap between clinically assessed physical performance and objective physical activity in liver transplant candidates. Liver Transplantation, 22(10):1324-1332, 2016.
[3] C. C. Schag, R. L. Heinrich, and P. A. Ganz. Karnofsky performance status revisited: reliability, validity, and guidelines. Journal of Clinical Oncology: Official Journal of the American Society of Clinical Oncology, 2(3):187-193, March 1984.
[4] Chiara M. Kelly and Armin Shahrokni. Moving beyond Karnofsky and ECOG Performance Status Assessments with New Technologies. Journal of Oncology, 2016:e6186543, March 2016. Publisher: Hindawi.