Bio-speckle phenomena and their application to the evaluation of blood flow

Aizu, Yoshihisa; Asakura, Toshimitsu

doi:10.1016/0030-3992(91)90085-3

Cited by 158 publications

(71 citation statements)

References 21 publications

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“…Another descriptor of the PSD is the mean frequency (MF) introduced by Aizu and Asakura 18 , defined as…”

Section: Mean Frequency (Mf)mentioning

confidence: 99%

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Signal Feature Extraction Using Granular Computing. Comparative Analysis with Frequency and Time Descriptors Applied to Dynamic Laser Speckle Patterns

Pra¹,

Passoni²,

Sendra³

et al. 2015

IJCIS

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The laser dynamic speckle is a phenomenon caused by the fluctuant interference of the laser light reflected from an illuminated surface where some kind of activity is taking place. Signals generated by the intensity changes in each pixel through the sequence are processed with the finality of identifying underlying activity in each point. In this work we compare the performance of a Rough Fuzzy Granular Descriptor (previously published) against a set of dynamic speckle descriptors based in time and frequency processing. To perform this evaluation a numerical simulation is proposed to explore their linearity, robustness, sensitivity related to the samples quantity, as well as also by their computing time. Also the robustness to inhomogeneous spatial intensity was evaluated in an experiment performed with the illuminated surface of an actual biological object.

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“…Another descriptor of the PSD is the mean frequency (MF) introduced by Aizu and Asakura 18 , defined as…”

Section: Mean Frequency (Mf)mentioning

confidence: 99%

“…This descriptor computes the frequency at the half of the PSD maximum, hence this procedure is analogous to the FWHMA, but applied now to the PSD instead of the autocorrelation 18 …”

Section: Cutoff Frequency (Cf)mentioning

confidence: 99%

Signal Feature Extraction Using Granular Computing. Comparative Analysis with Frequency and Time Descriptors Applied to Dynamic Laser Speckle Patterns

Pra¹,

Passoni²,

Sendra³

et al. 2015

IJCIS

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“…By 1975 speckle pattern started to be useful as information to monitor small changes in illuminated objects (Briers, 1975), and it was named dynamic laser speckle or biospeckle laser (BSL) (Aizu;Asajura, 1991) when applied to biological material.…”

Section: Introductionmentioning

confidence: 99%

“…BRAGA JÚNIOR, R. A Applications in Biosystems Braga, 2008) became well known in the literature from medicine (Aizu;Asakura, 1991;Fujii et al, 1987) to agriculture (Oulamara;Tribillon;Duvernoy, 1989;Zdunek et al, 2014), measuring many sample attributes under observation. Thus, the complexity of biological tissues or cells represents great challenge to identify or isolate the major phenomenon responsible for the boiling effect in speckle changes (Cardoso et al, 2011;Braga et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

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

Braga

Alves²

2017

Ciênc. agrotec.

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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 ...

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“…Através dos trabalhos que se seguiram, buscou-se dominar a técnica, além de descobrir novas aplicações para o uso do laser e de desenvolvimento de métodos de análise do speckle dinâmico, como instrumento de medição da atividade biológica como, por exemplo, os trabalhos de Fujii et al (1985), Oulamara et al (1989), Aizu & Asakura (1991), Arizaga et al (1999) dentre outros trabalhos.…”

Section: Introductionunclassified

Avaliação da interferência do laser no material biológico vivo

Botega¹,

Braga²,

Machado³

et al. 2009

Rev. bras. eng. agríc. ambient.

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RESUMOAlgumas das características especiais do laser associadas a fenômenos ópticos, permitem uma série de aplicações na área biológica, baseadas no fenômeno conhecido como "biospeckle". A técnica do biospeckle tem sido desenvolvida como uma ferramenta para análise da atividade de materiais biológicos, monitoramento de umidade, nível de atividade e presença de parasitos, dentre outros atributos. Apesar do monitoramento ocorrer através da iluminação do material por uma fonte de laser de baixa potência, a influência da luz na atividade biológica do espécime passa a ser sempre uma variável a ser investigada. Com este trabalho se objetivou avaliar a influência do laser na análise da atividade biológica medida pelo biospeckle de um tecido vegetal, caso em que uma folha de planta de café teve, como parâmetro, o tempo de iluminação. Utilizaram-se duas abordagens de iluminação, a primeira incidindo só o laser na folha e a segunda tendo o laser incidindo com uma fonte de luz não coerente, iluminando o ambiente. Pelos resultados experimentais verificou-se que os dados da atividade não exerceram influência significativa com a incidência do laser nem da luz, não coerente ao longo do tempo. Palavras-chave: biospeckle, análise de imagem, caféEvaluation of the influence of laser in live biological materials ABSTRACT Some of the special characteristics of the laser associated with optical phenomena allows a series of applications in the biological area, based on the well-known phenomenon biospeckle. The technique of biospeckle has been developed as a tool for analysis of biological materials activity for the checking of moisture, level of activity, presence of parasites, among other attributes. Although the monitoring occurs by illuminating the material with a source of low power laser, the influence of the light on the specimen's biological activity becomes always a variable to be investigated. This work had as its objective to evaluation the influence the laser in the analysis of the biological activity measured by the biospeckle of a vegetal tissue; in this case a leaf of coffee plant, using the illumination time as parameter. Two ways of illumination had been used, the first one being reflecting only the laser on the leaf; and the second one the laser reflecting with a source of non-coherent light illuminating the environment. From the experimental results, it was verified that the data of the activity did not have any significant influence with the incidence of the laser, as well as of the non-coherent light throughout the time.

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Bio-speckle phenomena and their application to the evaluation of blood flow

Cited by 158 publications

References 21 publications

Signal Feature Extraction Using Granular Computing. Comparative Analysis with Frequency and Time Descriptors Applied to Dynamic Laser Speckle Patterns

Signal Feature Extraction Using Granular Computing. Comparative Analysis with Frequency and Time Descriptors Applied to Dynamic Laser Speckle Patterns

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

Avaliação da interferência do laser no material biológico vivo

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