Development of Non-Contact Device Based on Optical Fibre Technology for Detecting Respiration of Small Animal in Imaging Instruments

摘要

Pre-processed images obtained from preclinical studies contain non-desirable artefacts due to the presence of pressure sensing parts of a respiration detector. Nonetheless, respiration monitoring is inevitable in imaging procedures, as it provides realtime information about changes in animals' wellbeing. Several imaging techniques have been adopted into developing alternative devices for measuring heart and respiration rates. One of the studies mention the use of optical fibres, by attaching fibres to a modified chamber structure. The fibres are still closely attached to a mouse and possibly cause artefacts. A pair of optical fibres are placed above the mouse, are connected to a fibre optic sensor which consists of an LED and a photodiode, and therefore can detect movement of abdominal walls and thus the respiration (Fig. 1(a)). In this paper, we propose to introduce an easy-to-integrate design of a non-contact respiration detector based on this principle. The concept of the initial design and experiments were constructed from mouse and Nano PET/CT (Fig. 1(b)), since mice are the focus of current preclinical research. A set of experiments were conducted to find sets of fibre arrangements that produce large voltage variations of the fibre optic sensor with respect to small movement changes regarding different fur colours. The selected fibre positions were later tested in a mouse simulation model to accredit acquired results and to possibly use on a real device. The toy filling in a model mouse was replaced with partially inflating balloon and mouse's breathing behaviour was controlled by using a pumping mechanism.