The Development of a Novel Sleep Position Monitoring Sensor

Author: Amelia Carter

Carter, Amelia, 2022 The Development of a Novel Sleep Position Monitoring Sensor , Flinders University, College of Science and Engineering

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Obstructive Sleep Apnoea (OSA) is a prevalent public health issue, with 60% of cases due to sleeping supine predominant, a condition termed positional OSA (Heinzer et al., 2018). To correctly diagnose this condition, it is essential that body position during sleep is accurately monitored, as well as non-invasively. This is a broad and growing area of research with multiple technologies posing solutions. However, there are still several challenges and shortcomings in current technologies. These include, privacy, usability, the need for personalised training of classification models, high-cost and complex signal processing. Consequently, current methods for monitoring body position are deficient.

This thesis describes the evolution of a novel sleep position monitoring system over three iterations. The research commences with a systematic literature review to identify and evaluate the current technologies in this field. The review is followed by a needs analysis. The major project stakeholders of end-users and sleep health experts completed questionnaires to aid in understanding project requirements. From these findings the sensor was designed to be a wearable that mounts directly to the skin over the sternum.

An important body of the thesis is the iterative design process to produce a novel first prototype of a sensor that meets the requirements identified from the review and customer analysis. The developed sensor has gone through extensive evaluation over multiple iterations to ensure the shortcomings of existing methods are met. To test the reliability and repeatability of the developed prototype a custom 3D printed testing mount was designed and developed. Resolution tests conducted at 15º and 30 º show that the sensor is able to repeatably and accurately realise position. Calibration tests conducted show that the sensor is successfully able to apply offsets to all positions to make data straightforward to interpret. A low standard deviation of measurements shows good agreement between the expected and measured position. Ultimately, the efficacy of the developed technology needs to be validated. Future work identified involves a miniaturised and precision manufactured iteration to be developed and tested on human subjects in overnight studies.

It is believed that this initial design is a step towards the realisation of a body position sensor that is simple, unobtrusive and enables easy calibration. There is the potential for the sensor to be used in other applications including positional OSA treatment and sudden infant death syndrome (SIDS) prevention.

Keywords: Positional obstructive sleep apnoea, body position monitoring, position sensor, obstructive sleep apnoea monitoring

Subject: Medical Biotechnology thesis

Thesis type: Masters
Completed: 2022
School: College of Science and Engineering
Supervisor: Professor Karen Reynolds