When noise became information: State-of-the-art in biospeckle laser

Abstract

Laser was presented to science and industry in the 1960s and shortly became a useful tool in many areas, with applications based on its multiple characteristics such as coherence of light, which presents a phenomenon known as interference pattern, or speckle, when beam returns from an illuminated surface. Despite great application of speckle pattern, its residual presence, for example, in interferometric approaches was considered as a noise, demanding filtering. However, grains themselves became information as their dynamic changes in time started to be linked to biological sample activity. Dynamic laser speckle has been since then a phenomenon widely used to monitor biological activities in many areas from agriculture to medicine. It is known as biospeckle laser (BSL) when adopted in biological material, with high sensitivity to follow very tiny movements in biological tissues, linked to changes in speckle provided by scatterer activities inside and outside cells. Since the 1970s, biospeckle laser usage follows a crescent technologic spiral where technological developments opened room for new applications, while new demands regarding biological monitoring forced the development of new methodologies. Therefore, potential adoption of the phenomenon as a sensor, for instance, in agricultural and medical processes, as well as constant offer of new devices provided new turns in the BSL technologic spiral and opened room for technique improvement. In this study, I present a short history of biospeckle laser (BSL) with applications and development associated with challenges regarding its usage in portable and accessible devices or even in commercial equipment. And the history was packed in a temporal diagram identifying the breakpoints responsible for improvements in the use of the technique.Index terms: Optical metrology; biosystems; challenges. RESUMOO laser foi apresentado à ciência e à indústria em 1960, e rapidamente tornou-se uma ferramenta útil à muitas áreas do conhecimento, que fazem uso de suas múltiplas características, como é o caso da coerência da luz, que é responsável pelo fenômeno conhecido como padrão de interferência, ou speckle; este padrão de interferência ocorre quando a luz retorna do material iluminado formando uma figura de interferência para o observador. Apesar da grande aplicação, a presença residual do padrão de speckle em abordagens interferométricas apresentavase como um ruído que demanda filtragem. Apesar da dificuldade em alguns casos, os grãos de speckle tornaram-se fonte de informação em situações dinâmicas, quando suas mudanças começaram a ser relacionadas à atividade do material biológico iluminado. Speckle laser dinâmico tornou-se o termo usado para denominar o fenômeno que passou a ser usado para monitorar a atividade biológica e não biológica em aplicações desde a agricultura até aquelas relacionadas à medicina. Este fenômeno também é conhecido como biospeckle laser (BSL), quando aplicado em material biológico, e com grande sensibilidade para seguir os menores movimentos ...

Biospeckle Analysis and Biofilm Electrostatic Tests, Two Useful Methods in Microbiology

“…Nevertheless, an increasingly growing field has emerged, pushed by the need to bring speckle-imaging capabilities out of the lab. In reference [81], Braga et al developed a portable device, smartphone-based, for DLS data acquisition and analysis, with the ability to set camera parameters and extract frames from recorded videos, pivotal for a portable solution [83].…”

“…and provides an objective, quantitative measure of speckle temporal changes due to bioactivity [48,86]. Although not recent, monitoring the biological activity by dynamic biospeckle is a still-growing field broadly discussed and intensely employed in many areas of knowledge [83].…”

Evaluation of 3D/2D Imaging and Image Processing Techniques for the Monitoring of Seed Imbibition

“…When the microrugosity evolves over time, cross-correlation calculations enable one to evaluate the decorrelation speeds of such temporal evolutions. Therefore, the biospeckle laser is an imaging technique widely used to monitor biological activities in different research domains such as medicine or agriculture [37,38]. With a high sensitivity to follow very tiny movements in biological tissues, this technique is well-adapted for microscopic characterization of biological samples and phenomena such as bacterial spreading [39] or for the detection of drug action on parasites [40].…”

Biospeckle Laser Technique for mechanical damage assessment in Tommy atkins mango fruits

“…The Biospeckle Laser (BL) technique is based on the optical interference phenomenon that occurs when a coherent beam of light strikes a dynamic surface or a biological material (Rabal & Braga Júnior, 2008;Braga Júnior, 2017;Rivera et al, 2019).…”