PT  - JOURNAL ARTICLE
AU  - Vitaly Voloshin
AU  - Christian Kröner
AU  - Chandrabhan Seniya
AU  - Gregory P. D. Murray
AU  - Amy Guy
AU  - Catherine E. Towers
AU  - Philip J. McCall
AU  - David P. Towers
TI  - Diffuse retro-reflective imaging for improved mosquito tracking around human baited bednets
AID  - 10.1101/691949
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 691949
4099  - http://biorxiv.org/content/early/2019/07/04/691949.short
4100  - http://biorxiv.org/content/early/2019/07/04/691949.full
AB  - Robust imaging techniques for mosquito tracking around human baited bednets are important for the development and understanding of interventions to mitigate vector-borne disease transmission. Whilst there have been recent innovations in optical imaging systems and associated signal processing, there remain issues around ease of use in the field and reliability of extracting data in the critical areas across the bednet where the optical signal is attenuated. In this paper we describe the use of a retro-reflective screen at the back of the measurement volume to simultaneously provide diffuse illumination, largely remove optical alignment issues and require only one sided access to the measurement space. Whilst the illumination becomes significantly more uniform, noise removal algorithms are needed to reduce the effects of shot noise particularly across the low intensity bednet regions. By systematically introducing mosquitoes in front and behind the bednet in lab experiments we are able to demonstrate the performance of the tracking system in these challenging areas. Overall, it is shown that the retro-reflective imaging setup can deliver mosquito segmentation rates in excess of 90% compared to less than 70% for previous back-lit systems.