Laser speckle

Monson E, Kopehnan IL (2000) Observation of laser speckle effects and nonclassical kinetics in an elementary chemical reaction. Phys Rev Lett 85 666-669. 

Another study aimed to evaluate and compare the effect of tafluprost, latanoprost, and travoprost on optic nerve head (ONH) blood flow in rabbits [42], A quantitative index of blood flow, squared blur rate (SBR), was determined with the laser speckle method, when 50pl of 0.0015% tafluprost, 0.005% latanoprost, or 0.004% travoprost were topically administrated once a daily for 28 days. After 28 days administration of tafluprost, latanoprost, and travoprost, the trough SBR values became 111.9 3.9%, 107.2 + 4.3% and 106.7 3.5%, respectively, compared with the value before administration. Sixty minutes after final administration on day 28, the SBR value with tafluprost, latanoprost, and travoprost become 116.1 + 3.5%, 106.1 3.0%, and 104.2 3.7%, respectively, compared with the value before administration. These results indicate that topical administrations of these compounds stably increase the ONH blood flow in rabbits. The magnitude of increase in ONH blood flow produced by tafluprost was greater than that of latanoprost or travoprost. 

One important point that should be noted is that optical mixing experiments cannot be used to find the direction of V since Si(q, (o) is unchanged when V—> — V. In principle, filter experiments would give the direction of V since the spectrum of Ffq, t) not ReFs (q, t) is measured in these experiments. Since the applications that we discuss involve polymers, the motions are too slow for filter methods. The direction of the velocity can be determined by observation of the sense of motion of the laser speckle patterns. 

J.C. Dainty, editor. Laser speckle and related phenomena. Berlin Springer, 1984. 

Using the laser speckle photographic method, Atapattu etal. [1995] measured point velocities in the fluid near a sphere moving at a constant speed... 

Have you considered using the camera for laser speckle strain measurement ... 

Fig. I. Stress-strain curves for (0001) AhOi using Yamaguchi s laser-speckle technique. Data have been shifted an arbitrary amount of pre-load to clearly show the data. Individual points represent the experimental data the straight lines represent the lea.st-squares fit.

Barranger, J.P. (1990) Two-dimensional surface strain measurement based on a variation of Yamaguchi s laser-speckle strain gauge. NASA TM-103162. 

Sayir, A., Greer III, L.C., Goldsby, J. and Oberle, L. (1994) Laser speckle micro-strain measurements on small diameter fibers. Ceram. Eng. Sci. Proc., 18 397-410. 

Binnington, R. J., G. J. Troup and D. V. Boger, A Low Cost Laser-Speckle Photographic Technique for Velocity Measurement in Slow Flow , J. Non-Newtonian Fluid Mech. 12 255-267 (1983). 

Volume 9 Laser Speckle and Related Phenomena Editor J. C. Dainty... 

Tripathi MM, Hajjarian Z, Van Cott EM, Nadkami SK. Assessing blood coagulation status with laser speckle rheology. Biomed Opt Express 2014 5 817-31. 

DBA can be integrated into tunable optical devices including laser speckle reducers and lenses, as described below. 

To reduce this problem, the company Optotune AG has developed and commercializes a DEA-based Laser Speckle Reducer (LSR) (Optotune 2015). The device functions in a similar way to a rotating difiiiser, although it is more compact and economical. A diffuser is mounted on an elastic membrane and set into eireular motion using four planar DBAs (actuating sectors), as illustrated in Fig. 12. 

Fig. 12 Working principle of the laser speckle reducer (a) no voltage is applied and the diffuser is centered (b) the upper actuating sector is active, translating the diffuser downward (c) fwo sectors are active which resulfs in a franslafion of fhe diffuser fo fhe bottom right comer (d) fhe left sector is active giving a franslafion fo fhe right. Alternation of fhe activation of fhe sectors resulfs info a circular motion of fhe diffuser...

Fig. 13 Optofune s laser speckle reducer LSR-3000 wifh an aperture of 5 mm. Attached fo fhe side of fhe recfangular sfmcfure fhe necessary elecfronics fo drive fhe LSR is visible...

A variety of applications of DEs have been reviewed covering a wide range of fields, ineluding robotics, tactile displays, fluid eontrol, sensors, and generators. While new design and applications are continuously been introduced, some of these applieation concepts are gradually been transitioned into commereial produets. Examples include capacitive sensors for human motion measurement produced by the eom-pany StretchSense, laser speckle reducers produced by the company Optotune, and headphones being developed by the company Artificial Muscle Inc. 

Q. Luo, H. Cheng, Z. Wang, and V.V. Tuchin, Laser Speckle Imaging of Cerebral Blood Flow, Chapter 5 in Coherent-Domain Optical Methods Biomedical Diagnostics, Environmental and Material Science, V. V. Tuchin (ed), Kluwer Academic Publishers, Boston, vol. 1, 2004, pp. 165-195. 

Particle Tracking Velocimetry and Laser Speckle Vehcimetry. 

Laser Speckle Contrast Imaging for Perfusion Monitoring in Burn Tissue... 

Abstract— Modeling and monitoring of blood perfusion in burn skin has been presented in this study. A non invasive Laser speckle contrast imaging (LSCI) system is presented here for monitoring different flovr conditions in a burn layer simulated capillary phantom. Speckle contrast variations vrith respect to changes in burn depth and blood perfusion rate have been studied in this vrork. 

Keywords— Laser speckle, LSCI, blood perfusion, tissue phantom, burn vrounds. 

David Briers J, Sian Websto" (1996) Laser speckle contrast analysis (LASCA) A non-scanning full field technique for monitoring capillary blood flow. J Biomed Optl 174-179... 

Pencheng li, SongUn Ni et al (2006) Imaging cerebral blood flow through the intact rat skull with temporal laser speckle imaging. Opt Lett31 1824-1826... 

Zakharov P, Volker A C et al (2009) Dynamic laser speckle imaging of cerebral blood flow. Opt Expressl7 13904-13917... 

Andrew K Dunn, Hayrunnisa Bolay et al (2001) Dynamic imaging of cerebral blood flow using laser speckle. J Cereb Blood Flow Me-tab21 195-201... 

Jayanthy A K, Sujatha N, Ramasubba Reddy M (2010) Laser speckle contrast imaging based blood flow analysis in normals and in patients with skin diseases, WASET Proc. vol. 69, International Conference on Computer, Electrical, and Systems Science, and Engineering, Singapore, 2010, pp 80-82... 

Nadkarni S K et al (2005) Characterization of artherosclerotic plaques by using laser speckle imaging. Circulation 12 885-892... 

Leonard W Winchester, Nee Yin Chou (2006) Monitoring free tissue transfer using laser speckle imaging. SPIE Proc. vol. 6078, Photonic Therapeutics and Diagnostics H San Jose, CA, LISA 2006, pp60780G-l-60780G-8... 

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